Construct Perpendicular and Parallel Lines in Cabri Jr.
You can construct perpendicular or parallel lines in the Cabri Jr. geometry application on the TI-84 Plus calculator. To construct such lines, you have to start with an already constructed line, segment, or side of a triangle/polygon.
To construct a line that is perpendicular or parallel to an already constructed line, segment, or side of a triangle/polygon, follow these steps:
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Select the appropriate tool from the F3 menu.
To do this, press [ZOOM]. Use
to move the cursor to the tool you wish to use and press [ENTER]. A picture of the tool you selected appears in the upper-left corner of the screen. The first picture illustrates that the Perp tool is active and waiting for you to construct a perpendicular line.
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Use the arrow keys to move the cursor to the already constructed line, segment, or side of a triangle/polygon.
The line or segment appears as a moving dashed line and the cursor changes to a solid arrow, as illustrated in the first picture.
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Press [ENTER].
A perpendicular line appears at the location of the cursor, as illustrated in the second picture. It appears as a dotted line, indicating that it has not yet been placed where you want it.
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If necessary, use the arrow keys to move the line to the location on the screen where you wish to construct the perpendicular or parallel line. Press [ENTER] to anchor this location.
If you are moving the line to an already constructed point, you know you have reached that point when the point begins to blink. Press [ENTER] when the line is at the desired location. The third picture illustrates this step when constructing a perpendicular line.
After constructing a parallel or perpendicular line, the tool you were using remains active until you deactivate it. So if you want to construct more objects of the same kind, just repeat Steps 2 through 4. When you are finished using that tool, you deactivate it by pressing [CLEAR] or by selecting another menu item.
