Why do schools teach Pythagorean Theorem?

Schools teach the Pythagorean Theorem because it is a fundamental mathematical concept that is used in many areas of mathematics, science, and engineering. It is a useful tool for solving problems involving right triangles, and it can be used to calculate the length of a side of a triangle when the lengths of the other two sides are known. Additionally, understanding the Pythagorean Theorem can help students develop a better understanding of geometry and trigonometry.