Learning goals: Teacher Facing Draw and label images of triangles under rigid transformations and then describe (orally and in writing) properties of the composite figure created by the images. Generalize that lengths and angle measures are preserved under any rigid transformation. Identify side lengths and angles that have equivalent measurements in composite shapes and explain (orally and in writing) why they are equivalent. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from 8.1 Rigid Transformations and Congruence, Grade 8.