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CABRIGEOMETRY II
Guidebook
for Macintosh
and MS-DOS
ë
ë
, Windowsë,
Dive into Geometry
About Cabri Geometry II
Cabri Geometry II lets you construct and explore geometric objects interactively.
Jean-Marie Laborde and Franck Bellemain developed Cabri Geometry II at the Institut
d'Informatique et Mathématiques Appliquées de Grenoble (IMAG), a research lab at the Université
Joseph Fourier in Grenoble, France, in cooperation with the Centre National de la Recherche
Scientifique (CNRS) and Texas Instruments.
Texas Instruments, the publisher for Cabri Geometry II in the United States and Canada, is pleased
to bring computer-based geometry to classrooms. The geometric foundation of this easy-to-use
software encourages exploring and conjecturing—from simple shapes to advanced projective and
hyperbolic geometry.
About the Developers
Jean-Marie Laborde is founder and Research Director of Laboratoire de Structures Discrètes et de
Didactique (LSD2), a research laboratory within IMAG. He graduated in mathematics at Ècole
Normale Supérieure in Paris in 1969. He earned a Ph.D. (Thèse d'État) in computer science at the
University of Grenoble in 1977. Jean-Marie began work on the Cabri II project in 1981 as an
environment for graph theory. He has devoted his research efforts to the use of geometric methods
for the study of different classes of graphs, especially hypercubes.
Franck Bellemain earned a Ph.D. in mathematics at the Université Joseph Fourier in 1992. He
began work on the Cabri II project in 1986 and is responsible for writing several versions of the
software for Macintosh, PC-compatible, and Japanese computers. His research and thesis have
been devoted to the use of technology in the classroom.
Cabri Geometry II Features
¦ Includes interactive analytic, transformational, and Euclidean geometry.
¦ Allows intuitive construction of points, lines, triangles, polygons, circles, and other basic
objects.
¦ Translates, dilates, and rotates geometric objects around geometric centers or specified points
plus reflection, symmetry, and inverse of the objects.
¦ Constructs conics easily, including ellipses and hyperbolas.
¦ Explores advanced concepts in projective and hyperbolic geometry.
¦ Annotates and measures figures (with automatic updating).
¦ Uses both Cartesian and polar coordinates.
¦ Provides for user display of the equations of geometric objects, including lines, circles,
ellipses, and coordinates of points.
¦ Allows the user to create macros for frequently repeated constructions.
¦ Lets the teacher configure tool menus to focus student activities.
¦ Checks geometric properties to test hypotheses based on Euclid’s five postulates.
¦ Hides objects used in constructions to reduce screen clutter.
¦ Differentiates objects through the use of paint-like color and line palettes.
¦ Computes a locus continuously.
¦ Illustrates the dynamic characteristics of figures through animation.
¦ Allows the user to save drawings and macros to disk.
¦ Opens geometry constructions created on the TI-92.
¦ Provides one square meter of full-size work space, and prints the 8.5 by 11.0 inches (21.59 by
27.94 cm) drawing area.
Copying permitted provided TI copyright notice is included
The Cabri Geometry II Guidebook contains user information about the Cabri Geometry II
software. It provides descriptions, procedures, illustrations, and examples for using the software
features on Macintosh computers, and Windowsé and MS-DOSë-based PCs.
4 Many of the procedures, illustrations, and examples are virtually the same for the different
computer types. Significant differences between the Macintosh, Windows, and DOS versions
are identified for your convenience.
4 Most of the illustrations are from the Macintosh version; several are from the Windows and
DOS versions. Due to space limitations, we could not show every illustration for each version.
Therefore, some illustrations in this guidebook may be slightly different on your computer.
4 Key names are shown in small capital letters such as
Escape key. The
the same function. In this guidebook, “Press
Structure
The Cabri Geometry II Guidebook contains the following chapters and appendices:
4 Chapter 1 describes the basic operations for using Cabri II, starting with checking system
requirements for installing the software, through constructing objects, to saving and printing a
construction file.
4 Chapter 2 describes the Cabri II menus and provides step-by-step procedures for using them.
4 Chapters 3 through 13 describe the Cabri II tools and provide step-by-step procedures for
using them. Each chapter discusses a specific group of Cabri II tools.
Definitions
The following definitions will help you in your understanding of this guidebook.
pointWhen used as an instruction, point means to place the screen pointer on
clickClick means to press and release the mouse button quickly, usually when
double-clickDouble-click means to click the mouse button twice in succession.
RETURN
key on the Macintosh and the
ENTER
top of the object you wish to select.
pointing to a specific location
CTRL
for the Control key and
ENTER
key on the PC keyboard perform
” means to press either
ENTER
ESC
or
for the
RETURN
.
vi
dragDrag means to point to the object you want to drag, press and hold the
mouse button to select the object, and move the screen pointer to a new
location. Release the mouse button to stop dragging.
modifyWhen used as an instruction, modify means to change the appearance,
size, location, or orientation of the object.
marquee outlineMarquee outline is the outline of an object in animated dots, similar to a
movie marquee.
marquee rectangleMarquee rectangle is the selection rectangle that appears when you drag
Pointer
with the
tool from an unoccupied location in the drawing window.
When you release the mouse button, objects that lie completely within
the rectangle are selected.
Copying permitted provided TI copyright notice is included
This chapter provides descriptions and examples of basic operations in Cabri Geometry II.
Becoming familiar with these items will enhance your usage. Differences between the Macintosh,
Windows, and MS-DOS versions are explicitly described where applicable. For convenience, DOS
will be used in the remainder of this guidebook to mean MS-DOS.
The following topics are discussed:
FIRST STEPSCONSTRUCTING OBJECTS
Checking system requirements
Installing Cabri Geometry II
Starting Cabri Geometry II
Optimizing your Macintosh system
configuration
Changing your Macintosh system
configuration using Cabri Geometry II
Using Cabri Geometry II on a network
The Cabri Geometry II window
Accessing on-line help
About menus and toolboxes
Pointers that guide you
Creating and selecting points
Handling ambiguities
Determining dependent and independent
objects
Dragging
Using the Undo/Redo command
Deleting objects
Changing the appearance of objects
Labeling objects
Scrolling the drawing window
Saving and printing
Classic. (Memory requirements will be
greater for color or larger monitors than on
the Classic.)
¦ Hard disk with 1.2 Mb available for
program and demonstration files.
Windows 3.1Windows 95
¦ 386 PC or better required; 486DX
recommended.
¦ PC must be in 386-Enhanced mode with
Virtual Memory enabled.
¦ VGA, SVGA video adapter and a color
monitor.
¦ 6 Mb RAM (minimum) memory installed.
¦ 7 Mb available hard disk space for program,
demonstration files, and system extensions.
¦ Mouse, or an equivalent pointing device.
¦ DOS-compatible computers (PCs), 386 or
better, and running MS-DOS 3.3 or later.
¦ EGA, VGA, SVGA video adapter and a color
monitor.
¦ 3 Mb RAM (minimum) memory installed.
¦ Hard disk with 2.5 Mb available for
program and demonstration files.
¦ Mouse, or an equivalent pointing device.
¦ 386 PC or better required; 486DX
recommended.
¦ VGA, SVGA video adapter and a color
monitor.
¦ 6 Mb RAM (minimum) memory installed.
¦ 2 Mb available hard disk space for program
and demonstration files.
¦ Mouse, or an equivalent pointing device.
Installing Cabri Geometry II
MacintoshDOS
1. Create a folder named
disk.
2. Insert the Cabri Geometry II Macintosh
diskette in your floppy disk drive.
3. Double-click on the
and follow the directions on the screen.
Windows 3.1Windows 95
1. Insert the Cabri Geometry II for Windows
diskette #1 in your floppy disk drive.
2. From Program Manager, click on
A:\SETUP
enter
prompts.
, and then follow the screen
Cabri II
Installer
on your hard
on the diskette
RUN
and
1. Insert the Cabri Geometry II DOS diskette
in your floppy disk drive.
2. At the DOS prompt, enter:
A:\INSTALL
follow the screen prompts.
1. Insert the Cabri Geometry II for Windows
diskette #1 in your floppy disk drive.
2. Click on
and then follow the screen prompts.
START/RUN
B:\INSTALL
or
and enter
, and then
A:\SETUP
,
Installing Cabri Geometry II on a network
If you have purchased the network license for Cabri Geometry II, you may run the software on
your network. Use network procedures that are compatible with your network to install Cabri
Geometry II. See your Macintosh, Windows, or DOS User’s manual or your network
documentation for more information, if necessary.
Note: Cabri Geometry II is supplied on high-density diskettes. If your computer will not accept
these diskettes, call, 1-800-TI-CARES and a service representative will supply you with low density
diskettes.
1-2 Chapter 1: Learning the Basics
Copying permitted provided TI copyright notice is included
1. Install Cabri Geometry II on the network server using the instructions given on the previous
page.
2. Run the program from the server the first time, and enter the requested information.
3. To run Cabri Geometry II on each network client, go to the directory on the network server
where the Cabri Geometry II application is installed. Macintosh users may double-click on
the Cabri II icon; DOS users may run Cabri2.exe to start the program.
The procedure described below, for Windows users, allows multiple client computers to run Cabri
Geometry II using the application software installed on the network server. Each client computer
is provided with the necessary system files to run Cabri Geometry II and a shortcut icon that is
linked to the application file on the network server.
Windows 3.1 and Windows 95
1. Install Cabri Geometry II on the network server using the instructions given on the previous
page. In the
Select Destination
screen, you must select a directory that will be accessible from each
client computer on the network.
2. Temporarily copy
setup.exe
and
setup.w02
from the installation diskettes to the same directory in
which you installed Cabri Geometry II in step 1.
3. On each network client, go to the directory on the network server that contains
setup.exe
and
double-click to on this file to run the setup program.
4. In the
Select Destination Directory
screen, click on the
Browse
button and select the same directory
that you used in step 1. Make sure the correct directory is displayed at the top of the window.
OK
You may edit the path, if necessary, and then click on
. Ignore the message that the directory
already exists.
5. In the
Select Components
screen, deselect the first three components. The installation program
will determine if the fourth component is necessary for Windows 3.1x users.
6. When Cabri Geometry II has been installed on all client computers, delete the two files that
were temporarily copied to the network server in step 2.
Starting Cabri Geometry II
MacintoshDOS
You can use one of four methods to start the
software on a Macintosh:
¦ Use
Open
¦ Double-click on the
¦ Double-click on any Cabri Geometry II
construction file, tool configuration file, or
macro file.
from the DOS
prompt directory where the Cabri Geometry II
files are located.
(Optional) Add the Cabri directory to your DOS
path to open Cabri Geometry II from any
directory.
Chapter 1: Learning the Basics 1-3
First Steps
(Continued)
Optimizing your Macintosh system configuration
If you are starting Cabri Geometry II on a Macintosh for the first time, you may need to make some
adjustments to make Cabri Geometry II compatible with your Macintosh computer system
configuration.
Graphics intensive programs require a large amount of memory to operate. The amount of memory
required directly relates to the size of your monitor and to the number of colors chosen to
represent graphical elements. Cabri Geometry II may require more memory than other applications
due to its interactive nature. Cabri Geometry II can assist you in optimizing your system.
If you see a warning message from the
configuration. This message indicates the amount of memory needed to run Cabri Geometry II
efficiently on your computer with your current configuration.
Click the
windows that are currently open. This frees the memory that these applications are using.
To change the amount of memory allocated to Cabri Geometry II, first make sure the
selected. Then, from the
decrease the application memory size to a value that is compatible with your computer.
Finder
, you need to make some adjustments to your system
OK
button to proceed (Cabri Geometry II does not start). Then close any applications or
Cabri II
Finder
, select
Get Info
in the
File
menu. Once the
Get Info
window appears,
icon is
If you are using System 7, an optional method is to use
Virtual Memory
to increase the amount of
memory available to applications. See your Macintosh User’s manual for more information.
The previous dialog box indicates the amount of available memory on your computer. You may
also select
About this Macintosh
in the
Apple
menu for the same information.
Changing your Macintosh system configuration using Cabri II
If you open Cabri Geometry II and the memory allocation on your Macintosh is not optimal, the
following dialog box appears. We recommend that you allow Cabri Geometry II to select optimal
Manual
parameters for your system automatically or that you select them using the
You may wish to quit and modify the settings yourself if you are familiar with the memory and
monitor control panels.
If you select the
Automatic
button, Cabri Geometry II computes the optimal settings for your
computer and then quits. The number of colors may change in the process of optimizing your
configuration. Double-click on the Cabri Geometry II icon for the changes to be applied to Cabri
Geometry II.
button.
Manual
If you select the
button, Cabri Geometry II continues to the optimization dialog box (see
example on the next page) that allows you to optimize your configuration as you want. Read the
items in the
Current Settings
field first, and then manipulate the other fields as described below the
example. (You can also access the following dialog box by pressing the
the software.)
1-4 Chapter 1: Learning the Basics
OPTION
Copying permitted provided TI copyright notice is included
The status indicates whether or not Cabri Geometry II can run with the
current settings.
# Screen Colors
Memory Setting
# Objects
# Colors
The number of colors used to display objects is directly related to the
amount of memory required to execute Cabri Geometry II. You can click
on the up or down arrow buttons in this field to change the number of
Status
screen colors. Check the
acceptable. Click on
OK
to continue.
field to determine if these values are
The amount of memory available and the number of colors displayed
determine the number of objects that can be constructed. You can click on
the up and down arrow buttons in this field to change the amount of
memory allocated to Cabri Geometry II. The value on the left indicates the
amount of memory required to run Cabri Geometry II on your computer in
black and white. The value on the right indicates the amount of memory
Status
currently available on your computer. Check the
OK
these values are acceptable. Click on
to continue.
field to determine if
The amount of memory available is directly related to the number of
objects that can be constructed. Click on this button to optimize the
number of objects that can be constructed. If memory is limited, Cabri
Geometry II will probably suggest that fewer colors be used to construct
more objects. For optimal performance, Cabri Geometry II attempts to
allocate enough memory to construct at least 300 objects.
The number of colors used to display objects is directly related to the
amount of memory required to execute Cabri Geometry II. Click on this
button to optimize the number of colors displayed. If you use other
applications regularly that require 256 colors, you may wish to optimize
the number of colors. Given limited memory, this decreases the number of
objects that you can construct.
The illustration below shows the Cabri Geometry II window. This window contains the essential
elements of the Cabri Geometry II software. A description of each element follows the illustration.
Note: The screen shown below illustrates the Macintosh version. Screens on Windows and DOS
systems are similar but slightly different.
Menu
Bar
Close
Box
Attribute
Icons
Drawing
Window
Help Icon
Toolbar
Zoom
Box
Attribute
Palette
This circle
Size
Box
Help Window
Elements of the Cabri Geometry II window
Drawing Window
Menu bar
1-6 Chapter 1: Learning the Basics
This region is where you build geometric constructions.
The menu bar contains common graphic user interface menus for file
management and editing, together with Cabri Geometry II options.
Scroll Bars
Pointer Message
Selection Pointer
Copying permitted provided TI copyright notice is included
The toolbar contains tools for building constructions. Eleven toolboxes
reside on the toolbar (see illustration below). To access a toolbox, press
and hold the mouse button on the icon. The items in that toolbox
appear.
Pointer
Points
Lines
Curves
Construct
Transform
Macro
Check Propert
Measure
Displa
Draw
Attribute icons
Help Icon
A
(Macintosh)
Help menu option
(Windows, DOS)
Selection pointer
Close box
Zoom box
(Macintosh, Windows)
Size box
(Macintosh, Windows)
Scroll bars
(Macintosh, Windows)
The attribute icons are not displayed unless you select the
command in the
Options
menu on the menu bar. These allow you to
Show Attributes
modify the appearance of objects. You can create an attribute palette
(tear-off menu) by dragging an icon from the attribute icons to the
drawing window.
Clicking on the help icon A creates a help window at the bottom of your
screen that contains useful help messages for each command. Clicking
on the A again removes the help window.
Clicking on the
Help
menu option and selecting
key toggles the help window ON and
OFF
Help
or pressing the
F1
.
The selection pointer is the primary tool for selecting menus and
building constructions. The shape of the pointer changes according to its
current operation and location.
The close box closes the window and creates a dialog box that allows
you to save your work if you have not done so.
The zoom box toggles the size of the window between the current size
and the full screen size.
Dragging the size box to a new location resizes the drawing window.
Clicking in the scroll bars or on the scroll arrows moves the contents of
the drawing window vertically or horizontally.
Operations are grouped by type in the pull-down menus located on the menu bar and on the
toolbar. Once a tool is selected, it remains active until you select another tool. If the icon of the
tool you want is shown on the toolbar, select it by clicking once on the icon. Commands in the
menu bar must be selected each time they are used.
Descriptions of the Cabri Geometry II menus and toolboxes follow:
MENUS
Apple
(Macintosh only)
File
Edit
Options
Window
(Windows)
Help
(Windows, DOS)
TOOLBOXESTools for ...
Pointer
Points
Lines
Curves
Construct
Apple menu items or the Cabri Geometry II logo screen.
Commands for opening, closing, saving, or printing constructions.
Commands for selecting or copying objects, refreshing the drawing window,
or replaying constructions.
Commands for tool configurations, hide/show attributes, preferences, or
setting software defaults (Macintosh only).
Several types of pointers exist to help guide you through your constructions. The pointers are
illustrated below.
PointerCursor looks like...
arrow
cross hair
construction pencil
selection pencil
pointing hand
selection hand
dragging hand
open hand
grasping hand
magnifying glass
I-beam
paint brush
!
$
&
%
(
)
*
"
#
'
I
The pointer is in the toolbar, menu bar, or
scroll bars.
Pointer
The
A construction tool is active.
A construction tool is active and a point can
be placed on an object.
A point can be selected.
An object is dependent or to show the
intermediate stage between selecting an
object and dragging.
An object can be moved.
The
(DOS) is pressed.
The window can be scrolled using the
mouse.
An ambiguity exists.
Text or numbers can be entered or edited.
Color or attributes can be changed.
tool is active.
COMMAND
key (Macintosh) or the
CTRL
paint bucket
crossed lines
column width
1
4
3
An object can be filled with a pattern or
color.
Comment
The
The column width of the table can be
adjusted.
option is active.
Creating and selecting point*s
All objects are constructed using one or more points. You create or select points when a tool is
active. In general, the order of operation is to select a construction tool from the toolbox, and then
to create or select the required points that define the tool.
A point is created by a single click of the mouse. You can create points in unoccupied space when
construction pencil
the
two objects when a cursor message appears and the pointer changes to the
The following examples illustrate how to create and select points.
# cursor is visible. You can create a point on an object or at the intersection of
selection pencil
' cursor.
1-10 Chapter 1: Learning the Basics
Copying permitted provided TI copyright notice is included
Example 1: Creating the perpendicular bisector of two
points
1.Select the
Perpendicular Bisector
tool from the
Construct
toolbox.
2. Move the # to any place in the drawing window and click
(not hold down) once.
A flashing point appears on the window, indicating that
this point has been selected for the construction.
3. Move to another place and click again.
A second point appears as well as the perpendicular
bisector of the segment connecting these two points.
(Note: The segment does not appear.)
If the pointer is near a valid object, a cursor message is
displayed. In some cases, it is sufficient to select only
one object to define a construction, as the next example
demonstrates.
Example 2: Creating the perpendicular bisector of a side of
a triangle
1.Select
Triangle
from the
Lines
toolbox.
2.Move the # to any place in the drawing window and
click. Move to a second location and click, and then to a
third location and click.
A triangle appears in the drawing window with the three
points selected as vertices.
Note: Depending on the speed at which you constructed
these three points, the sides of the triangle might appear
during the construction. Try doing this slowly and watch
the triangle materialize.
Perpendicular bisector of this side of the triangle
When the cursor is in unoccupied space in the drawing
window, the # appears. Move the cursor near a side of
the triangle. The cursor changes from the # to the $ with
the message
Perpendicular bisector of this side of the triangle
(If the cursor is near a vertex of the triangle, the cursor
message
This point
appears.)
Click once, and the perpendicular bisector of the side of
the triangle appears.
Handling ambiguities
appears.
Perpendicular bisector of this side of the triangle
.
When two or more objects simultaneously occur at the location of the pointer, the
* cursor and the cursor message
Which object?
appear. Press and hold down the mouse to see the
magnifying glass
options in a dialog box. Select an object by pointing to the appropriate choice in the box and
releasing the mouse.
When multiple objects are present, they are listed in the order in which they were created.
Selecting an object causes it to display in marquee outline. You can move (drag) it to a new
Pointer
location if it is an independent object and the
tool is selected. Click in unoccupied space to
deselect the object. If you are using a construction tool, the object is selected for the construction.
Determining dependent and independent objects
All objects are created using one or more points. The manner in which you create an object
determines whether it is dependent or independent of the object. This distinction becomes very
important with respect to dragging objects. An example of this distinction is given after the section
“Dragging.”
A point constructed by itself is called a basic point.
An independent object is an object created using only basic points. Independent objects can be
moved (dragged) but not modified directly. By moving the basic points used for their construction,
you can modify them indirectly.
A dependent object is an object constructed using an independent object (or another dependent
object). Dependent objects cannot be moved (dragged) or modified directly. You can move or
modify them indirectly by moving the basic points or independent objects responsible for their
existence.
The more elaborate a construction becomes, the more difficult it can be sometimes to distinguish
these types. However, the Cabri Geometry II software will assist you.
1-12 Chapter 1: Learning the Basics
Copying permitted provided TI copyright notice is included
Dragging objects is valuable for generating conjectures. You can modify an object by dragging all
or part of it to a new location. Whether or not an object can be changed depends directly on how it
was created.
You can drag (move) a basic point to a new location, modifying, in turn, any object constructed
Pointer
using it. An independent object can be modified with one of the tools from the
cannot alter a dependent object directly by dragging, but you can change it by dragging the basic
points used in its construction.
toolbox. You
Whenever an object can be dragged, the pointer changes to the
then to the
dragging hand
% cursor. When the % is visible, the selected object follows the pointer as
selection hand
& momentarily and
you move it.
If your computer's performance is sluggish, you may need to move the pointer to the location you
want and wait for the computations to finish with the new characteristics. This is particularly
evident when there are many objects in the drawing window.
If the object is dependent (cannot be dragged), the pointer changes to the
reverts to the
cross hair
! cursor.
selection hand
& and then
Example 3: Evaluating basic points, independent objects,
and dependent objects
1. Construct the perpendicular bisector of a side of a
triangle (see Example 2).
(The vertices are basic points, the triangle is an
independent object, and the perpendicular bisector is a
dependent object.)
2. Basic points:
Pointer
Select
from the
Pointer
toolbox.
Move the ! near a vertex of the triangle (the cursor
changes to the $ with the message
Press and hold down the mouse button.
The cursor changes to the & and then almost
immediately to the %.
When you drag the point, the triangle changes its size
and shape, and the perpendicular bisector changes
accordingly.
These results are characteristics of using a basic point.
An inquiry that could be made here is: “When does the
perpendicular bisector of one side of a triangle contain
a vertex of the triangle?”
Move the ! near a side of the triangle (the cursor
changes to the $ with the message
Press and hold down the mouse button.
The cursor changes to the & and then almost
immediately to the %.
Continue to hold down the mouse and move the triangle
about the drawing window.
The triangle does not change its size or its shape, while
the perpendicular bisector moves along with the triangle.
The triangle was constructed using three basic points as
its vertices; therefore, it is an independent object and
can be moved.
4.Dependent objects:
Move the ! near the perpendicular bisector (the cursor
changes to the $ with the message
Press and hold down the mouse button.
This triangle
This line
).
).
This line
The cursor changes to the & and then almost
immediately back to the !.
The perpendicular bisector cannot be modified directly;
it is a dependent object.
Note: You can modify the perpendicular bisector
indirectly by dragging the basic points or the
independent objects used for its creation.
Example 4: Creating the circumcenter of a triangle
1.Construct the perpendicular bisector of one side of a
triangle (see Example 2.)
2.Construct the perpendicular bisector of a second side.
1-14 Chapter 1: Learning the Basics
Copying permitted provided TI copyright notice is included
4.Point to one of the perpendicular bisectors (the cursor
message
This line
appears) and click once.
The line changes to marquee outline.
5.Point to the other perpendicular bisector. After the
cursor message appears, click once.
The first line returns to solid, and a point at the
intersection of the two lines appears. This point of
This line
intersection is known as the circumcenter of the triangle.
The vertices of the triangle are basic points. The triangle
is an independent object because its existence depends
only upon basic points. The perpendicular bisectors are
dependent objects because their existence depends upon
independent objects (the sides of the triangle). The
circumcenter is a dependent object because it was
created using dependent objects (the perpendicular
bisectors).
In Example 5, we will first create a circle, and then inscribe a triangle. You can move the circle by
dragging its center point or modify it by dragging its circumference. The triangle cannot be moved.
However, you can modify it by dragging any one of its vertices around the circle.
Example 5: Inscribing a triangle in a circle
1.Choose
Circle
from the
Curves
toolbox.
2.Move the # to any place in the drawing window and click
once.
A flashing point appears.
3.Move the cursor away from the flashing point.
A circle appears with the flashing point as its center.
Click again to finish constructing the circle.
Note: The flashing point changes to solid to indicate the
construction is completed.
5.Move the # to any point of the circle (the cursor message
On this circle
appears), and click once.
6.Move the cursor to a second and third point on the
circle, clicking once at each point.
A triangle becomes inscribed in the circle.
7.Choose
Pointer
from the
Pointer
toolbox.
8.Move the ! cursor near the center point (the cursor
message
This point
appears).
Press and hold down the mouse button until the %
appears, and drag the center point around the drawing
window.
On this circle
Note: The radius of the circle remains unchanged.
9.Move the ! near the circumference of the circle (the
cursor message
This circle
appears).
Press and hold down the mouse button until the %
appears, and drag the circumference.
Note: The center point of the circle remains fixed while
the radius changes, and the vertices of the triangle stay
on the circle.
10. Move the ! near a vertex of the inscribed triangle (the
cursor message
This point
appears).
Press and hold down the mouse button until the %
appears, and then drag the point.
Note: The point can only be moved along the circle.
If you move the pointer while creating points, Cabri Geometry II reverts to dragging. This feature
anticipates your intent to modify your construction without requiring you to return to the
Pointer
toolbox. However, it can create some confusion if you are creating points quickly and
inadvertently move the pointer while pressing the mouse. In this case, a point will not be created.
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You can cancel an operation that has just been completed by using the
Edit
menu. Only the most recent operation can be undone.
To review additional steps in your construction, see the
Replay Construction
Undo/Redo
command in the
command in the
Edit
menu. This command allows you to replay each step of a construction.
Deleting objects
Delete objects by selecting them, and then pressing
Edit
menu.
DELETE
or selecting the
Select multiple objects by pressing the mouse in free space and dragging a marquee rectangle
around the objects to be deleted. Only objects that are fully enclosed by the marquee rectangle will
be deleted. All selected objects are displayed in marquee outline.
Select all objects in the drawing window by using the
press
DELETE
pressing
pressing
or select
COMMAND+A
DELETE
.
Clear
from the
(Macintosh) or
Edit
menu. You can also clear the entire drawing window by
CTRL+A
(Windows, DOS) simultaneously, releasing, then
Select All
command in the
WARNING! When an object is deleted, all objects that depend on that object are deleted as well. It
is possible to delete an entire construction by deleting a single point. If you accidentally delete an
object, you can recover it by using the
Undo/Redo
command in the
Edit
menu.
Example 6a: Deleting objects — Method 1
Clear
command in the
Edit
menu. Then
1.Construct a circle and an inscribed triangle
(see Example 5).
2.Select
Pointer
from the
Pointer
toolbox.
3.Point to the center point of the circle and click.
The center point flashes.
Press the
DELETE
key.
The point, the circle, and the triangle disappear.
To apply attributes from tools in the
modified. To use an option from the
Hide/Show Attributes
Modify Appearance
, or
Draw
menu, select the tool, and then select the object to be
Attributes
toolbar, first select the objects to be modified, and
Attributes
toolbar or the
command in the
tools.
Draw
Options
toolbox.
menu. In the
then select the attribute.
Labeling objects
You can label points in two ways — as you create them or with the
Label
tool in the
Labeling objects as they are created is intended for quick access and is limited to five
alphanumeric characters. Editing is not available at this stage. However, after constructing the
Label
object, you can edit the label with the
tool.
Example 7a: Adding labels during construction
1.Select
Triangle
from the
2.Click on the drawing window. Then type
A point appears with a label
Lines
toolbox.
A
beside it.
A
.
Display
toolbox.
Draw
3.Move the # , click once, and then type
B
.
Another point, a segment connecting the two points,
B
and a label
4.Move the # to a new position, click once, and type
The completed triangle appears as well as the label
appear.
C
.
C
beside the last point created.
The
Label
tool in the
Display
toolbox allows you to attach labels to a point, line, or circle. Once
attached to the object, labels cannot be detached. You can position them near the object using the
Pointer
, and they will retain that position through all modifications to the object.
You can scroll the drawing window within a one-square-meter region by three methods:
4 Use the Show Drawing command in the File menu to view the entire one-square-meter region
in compressed form. You can reposition the active widow, which allows you to work in
another section of the drawing. (Note: When you click and hold the mouse button, the
grasping hand cursor ()) appears.)
4 Use the scroll bars on the right and bottom sides of the drawing window (Macintosh only).
Clicking on the scroll bars or buttons moves the drawing in a horizontal or vertical direction.
4 Press the
left mouse button. The screen scrolls in the direction that you move the pointer.
COMMAND
key (Macintosh) or the
key (Windows, DOS), then press down on the
CTRL
Saving and printing
You can save a construction to a file at any time using the
menu. If the construction has never been saved, these two commands have the same effect.
Save
The
stored. If the construction has already been saved, the
has been modified since the previous save. The new version of the construction replaces the older
one.
The
the older version.
You can print your Cabri Geometry II constructions on a printer. Printed constructions enhance
understanding by providing accurate, printed-to-scale manipulatives. The entire one-square-meter
drawing or a specified portion can be printed in both black and white, or color.
dialog box allows you to name the construction and to choose the folder where it will be
Save as...
command allows you to save the figure to another folder or name without deleting
Save
Save
command is active only if the figure
Save as...
and
commands in the
File
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