Students will see two proofs that the diagonals of a rectangle are congruent. Students will also learn how to apply the theorem to solve mathematical problems. Here's an easy but interesting problem:
Rectangle ABCO is inscribed in a quarter circle having radius 10. What is length AC?
The solution can be found here.
The original problem is #6 on this page, but the diagram is horrendous.
Conclude by giving your students these challenges: