Pythagorean theorem

In a right triangle, the square of the hypotenuse equals the sum of the squares of the legs.

The Pythagorean theorem states a² + b² = c², where a and b are the legs and c is the hypotenuse of a right triangle. It also gives the Euclidean distance between two points in the plane and underpins the formulas for vector magnitudes.

a² + b² = c²