Learning goals: Teacher Facing Comprehend that figures with the same area and perimeter may or may not be congruent. Critique arguments (orally) that two figures with congruent corresponding sides may be non-congruent figures. Justify (orally and in writing) that two polygons on a grid are congruent using the definition of congruence in terms of transformations. Full lesson plan (warm-up, activities, synthesis, cool-down prompt) from 8.1 Rigid Transformations and Congruence, Grade 8.