First, students will review the formula for the diagonal length of a rectangle. After that, students will learn how to use the Pythagorean theorem to find the length of an internal diagonal of a rectangular prism. Here's a problem where the rectangular prism is a cube. Here's a problem where both the right triangles within the rectangular prism are Pythagorean. Next, give your students this challenge. Finally, give them this one.
Conclude by giving your students these challenges: