Students will learn what the hypotenuse-leg theorem is, why it's true, and how to use it. The proof depends on the Pythagorean theorem.
Conclude by giving your students these challenges:
In the figure below, all the blue angles are equal. Mentally determine the angle.

Here's the answer:
Because the 3 pentagons fit together to form a full angle at the center, we know the top angle is \(360^\circ/3 = 120^\circ.\) We also know two of the angles are \(90^\circ,\) so adding those we get \(180^\circ.\) Adding \(120^\circ\) and \(180^\circ\) gives us \(300^\circ,\) so there are \(240^\circ\) degrees left to account for. But the blue angles are equal, so the missing angle must be half that, which is \(120^\circ.\)