Students often have an intuitive understanding of symmetry. Though students begin recognizing symmetric figures at an early age, the analytic understanding needed to confirm symmetry and to construct figures with given symmetries requires greater mathematical sophistication.

Kaleidoscopes, Hubcaps, and Mirrors, the last geometry and measurement unit in the Connected Mathematics curriculum, helps students to refine their knowledge of symmetry and to use it to make mathematical arguments.

Symmetry is commonly described in terms of transformations. Symmetry transformations include reflections, rotations, and translations. These transformations preserve both angle measures and side lengths, resulting in an image that is congruent to the original figure. This unit will stimulate and sharpen students’ awareness of symmetry, congruence, and their connections.