Caption:
Portrait of Pythagoras taken from a portion of a fresco by Raphael. The Greek philosopher and mathematician Pythagoras made very important developments in astronomy, mathematics, and the theory of music. He was the founder of the religious and scientific society called the Pythagoreans and is best known for the Pythagorean theorem. The Pythagorean Theorem describes the relationship between the sides of a right triangle. It is often related thusly: ''In any right triangle, the area of the square whose side is the hypotenuse is equal to the sum of the areas of the squares whose sides are the two legs.'' Colored Version of BD8033.