You can use the Appearance menu in the Cabri Jr. geometry application for the TI-84 Plus calculator to find distance and length of segments. The D. & Length tool in the Measure submenu of the Appearance menu is used to find the following measurements:

• The distance between two points

• The length of a segment

• The circumference of a circle

• The perimeter of a triangle or quadrilateral

To use the D. & Length tool, follow these steps:

1. Press [GRAPH] to select the Appearance menu. Use the

keys to place the cursor on the Measure option. Press

to display the Measure submenu. Use the

to place the cursor on the D. & Length option, and then press [ENTER] to select that option.

A symbol of the tool appears in the upper-left corner of the screen.

2. Select the object you want to measure and press [ENTER] to display the measurement. Use the arrow keys to move the measurement to a better location and press [ENTER] to anchor that location.

If you are measuring the distance between two points, use the arrow keys to move the cursor to the first point and press [ENTER] to select that point. Then move the cursor to the second point and press [ENTER]. The distance between the points appears on the screen. Use the arrow keys to move the measure of that distance to a better location and press [ENTER] to anchor that location.

If you are measuring the length of a segment, the circumference of a circle, or the perimeter of a polygon, use the arrow keys to move the cursor to that object. The cursor is on the object when the object blinks. Press [ENTER] to select the blinking object.

The requested measurement appears on the screen. Use the arrow keys to move that measurement to a better location and press [ENTER] to anchor that location. This is illustrated in the second picture, where Cabri Jr. found the circumference of the circle.

3. To measure another object, repeat Step 2.

4. When you are finished taking measurements, press [CLEAR] or select another menu item.

All measurements displayed on the screen of the calculator are only a one decimal place approximation of the true measure. So if, for example, you want to show that your right triangle satisfies the Pythagorean Theorem, you most likely will not be able to do this using the measurements displayed on the calculator’s screen.