Pythagoras was an ancient Greek philosopher, mathematician and founder of the Pythagorean brotherhood in the 6th century BCE. He established an academy in Croton, Italy that formulated principles influencing later thinkers like Plato and Aristotle. Pythagoras is best known for the Pythagorean theorem, which states that in a right triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides. The theorem is fundamental to mathematics and is used today to determine viewing sizes of televisions and identify right triangles through pythagorean triplets.