Pythagoras Pythagoras was a very significant person in the history of the world. He made many contributions to the fields of math, music, and astronomy. Pythagoras's teachings and beliefs that were once taught by him in his own school in ancient Greece, are still taught today. The thing that Pythagoras is probably the most famous for is the Pythagorean Theorem. The Pythagorean Theorem is used in the field of mathematics and it states the following: the square of the hypotenuse of a right triangle is equal to the sum of the squares of the two other sides. This means that if one makes a square (with all sides equal in length) out o