This document provides instruction on using the Pythagorean theorem and its converse to solve problems involving right triangles. It begins with examples of using the Pythagorean theorem to find missing side lengths of right triangles. It then discusses how to classify triangles as right, acute, or obtuse using Pythagorean inequalities. The document also covers identifying Pythagorean triples and solving application problems involving the Pythagorean theorem. Worked examples and practice problems are provided throughout for students to check their understanding.