Clear large transparent coordinate grid, class set of colored transparency polygons (square, rectangle, triangle, pentagon). Create polygons that have integral coordinates as vertices so that original and transformed vertices' coordinates are easier to read on the grids. Student sheets for recording.

Provide the class with a selection of transformations (such as 10 translations, 10 reflections, and 10 rotations, again, one for each student) and the set of colored transparency polygons.

• Each student selected will choose a polygon and a transformation.
   
• The student places the polygon on the coordinate grid transparency and gives the other students time to record the coordinate points for the vertices of the polygon in its starting position (original position). (Note: a numbered coordinate grid will be useful in the beginning).
   
• The student at the overhead performs the transformation and the other students record the new position (image) of the polygon, as well as the transformation performed. The teacher asks the students in the class if they agree with the result with the result of the transformation, and requires them to justify their responses.

Student sheets should have five columns: Presenter, Polygon, Starting Position, Transformation, and Ending Position. See the example below. Answers can be reviewed aloud as students can keep the card indicating their transformation until the end of class. Ask students what patterns they see in all of the translations, all of the rotations, and all of the reflections.

Example:

Sample correct responses:

• When translating to the right, the x-coordinate increases by the number of units of the translation
• When translating to the right, the x-coordinate decreases by the number of units of the translation
• When translating up, the y-coordinate increases by the number of units of the translation
• When translating down, the y-coordinate decreases by the number of units of the translation
• When reflecting across the x-axis, the y-coordinates of the ending position are the opposites of the y-coordinates of the starting position
• When reflecting across the y-axis, the x-coordinates of the ending position are the opposites of the x-coordinates of the starting position
• When rotating 90° clockwise, the x- and y-coordinates of the starting position and the ending position interchange and the ending position y-coordinates become opposite of the starting position x-coordinates
• When rotating 90° counterclockwise, the x- and y-coordinates of the starting position and the ending position interchange and the ending position x-coordinates become opposite of the starting position y-coordinates
• When rotating 180°, the x- and y-coordinates of the starting position are opposite of the ending position x- and y-coordinates