Online calculator which helps you calculate the length of the third side of a right triangle knowing the other two parties.

The Pythagorean theorem is one of the fundamental theorems of Euclidean geometry that defines the ratio between the sides of a right triangle: the sum of the squares of the lengths of the legs is equal to the squared length of the hypotenuse.

Can also be expressed as a geometric fact that the area of a square constructed on the hypotenuse equal to the sum of the areas of the squares built on the legs.

The converse is true: the triangle, the sum of the squares of the lengths of two sides is equal to the squared length of the third side is rectangular.