In mathematics the Pythagorean theorem, is a fundamental relation in Euclidean geometry  among the three sides of a right triangle . It states that the square of the hypotenuse  (the side opposite the right angle ) is equal to the sum of the squares of the other two sides The theorem can be written as an equation relating the lengths of the sides a, b and c, often called the “Pythagorean equation where c represents the length of the hypotenuse and a and b the lengths of the triangle’s other two sides.

Although it is often argued that knowledge of the theorem predates  the theorem is named after the ancient Greek mathematician Pythagorea (570–495 BC) as it is he who, by tradition, is credited with its first proof, although no evidence of it exists.