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Dragging
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
using it. An independent object can be modified with one of the tools from the Pointer toolbox. You
cannot alter a dependent object directly by dragging, but you can change it by dragging the basic
points used in its construction.
Whenever an object can be dragged, the pointer changes to the selection hand & momentarily and
then to the dragging hand % cursor. When the % is visible, the selected object follows the pointer as
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 selection hand & and then
reverts to the cross hair ! cursor.
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:
Select Pointer from the Pointer toolbox.
Move the ! near a vertex of the triangle (the cursor
changes to the $ with the message This point ).
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?"
Copying permitted provided TI copyright notice is included
© 1997, 1999 Texas Instruments Incorporated
This point
Chapter 1: Learning the Basics
1-13
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