## Geometry: Common Core (15th Edition)

The equation $a^2 + b^2 = c^2$ defines what is called the Pythagorean theorem. It relates the three sides of a right triangle to one another. The Pythagorean theorem states that the squares of the lengths of the two legs of a right triangle are equal to the square of the length of the hypotenuse. The numbers $a$, $b$, and $c$ must be greater than zero. If the values satisfy this equation, then we have a Pythagorean triple.