In Cabri Jr. on the TI-84 Plus, you can use the Area tool in the Measure submenu of the Appearance menu to find the area of an already constructed circle, triangle, or quadrilateral.

To use this 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


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

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

  2. Use the arrow keys to move the cursor to the object whose area you want to find and press [ENTER] to select that object.

    The object is displayed as a blinking object, and the requested area appears on the screen. This is illustrated in the first picture, where Cabri Jr. found the area of the circle.

  3. Use the arrow keys to relocate that measurement on the screen and press [ENTER] to anchor that location.

  4. To find the area of another object, repeat Steps 2 and 3.

    This is illustrated in the third picture, where the area of the triangle was found and labeled.

  5. When you are finished finding areas, press [CLEAR] or select another menu item.