No Bending, No Stretching

Students begin to see that translations, rotations, and reflections preserve lengths and angle measures, and students call them rigid transformations for the first time. Note: A paper version of this lesson is also available. The digital version requires a paper supplement.

By Desmos Classroom

Learning goals: Learning Goals • Observe that rigid transformations preserve lengths and angle measures. • Understand that all corresponding distances between pairs of points are equal in congruent figures. Materials • Geometry toolkits (particularly a protractor, tracing paper, or an index card)