How do i use the pythagorean theorem

The Pythagorean theorem is a² + b² = c². The c² is the hypotenuse of the triangle. For example, if the side lengths of the triangle are 2 and 4, the equation would then be 2² + 4² = c². You would then solve the equation by getting rid of the exponents. 4 + 16 = 20. Square root the 20, and that is your answer.

A2 plus B2 equals C2