Tile the Plane in GeoMaster on the TI-84 Plus

By C. C. Edwards

The Symmetry tool in the TRFM menu on the TI-84 Plus calculator can be used to tessellate (tile) the plane with a geometric figure by rotating that object 180 degrees about a specified point. Unlike the Rotation tool, the Symmetry tool displays both the original and rotated object.

To tessellate the plane with an already constructed polygon, follow these steps:

  1. Press [GRAPH][TRACE][5] to select the Symmetry tool from the TRFM menu.

  2. Use the arrow keys to move the cursor to the object you want to tessellate and press [ENTER].

    The object to be rotated appears as a dashed figure, as illustrated in the first image.


  3. Use the arrow keys to move the cursor to the point of rotation and press ENTER.

    The point of rotation is usually any vertex of the polygon. After you press [ENTER], the rotated figure appears, as illustrated in the second image.

  4. Repeat Step 3 until the plane is tiled.

    This is illustrated in the third image shown.

When you are finished tiling the plane, deactivate the Symmetry tool by pressing [CLEAR] or by selecting another menu item.