This is a tutorial video on how to write equations to solve for the unknown or missing side lengths of right triangles. The video explains the Pythagorean Theorem and the properties of right triangles, such as legs, hypotenuse, and the 90-degree angle. The tutorial also provides examples and a step-by-step guide on how to organize information in a table and apply the Pythagorean Theorem to create equations for solving for unknown side lengths.