Students will learn what the congruent complements and supplements theorems are, how to prove them, and how to use them. Before students attempt to understand the proofs, they should know what complementary and supplementary angles are. Here's a proof for the congruent complements theorem, and here's a nearly identical proof for the congruent supplements theorem. Here's an example of using the congruent supplements theorem (source):
Conclude by giving your students these challenges:
- Almost One by NRICH
- Great Granddad by NRICH
- Mobile Numbers by NRICH
- 2015 AMC 8, Problem 3
- 2012 AMC 8, Problem 19