This Instructional Activity is a part of the Lesson 16, Unit 7, Grade 8. So far you have seen three different proofs of the Pythagorean theorem. Provide students time to explain to a partner a proof of the Pythagorean theorem. Allow them to choose any one of the three proofs they have seen. Remind them of the proof from Module 2 that was based on congruent triangles, knowledge about angle sum of a triangle, and angles on a line. Also remind them of the proof from Module 3 that was based on their knowledge of similar triangles and corresponding sides being equal in ratio.