Pythagoras of Samos, "Pythagoras the Samian", (570- 495 BC) was a Greek philosopher and mathematician. Pythagoras has been given credit for discovering the Pythagorean theorem, a theorem in geometry that states that in a right-angled triangle the area of the square on the hypotenuse, the side opposite the right angle, is equal to the sum of the areas of the squares of the other two sides. The mathematical equation is written: a2 + b2 = c2.