<human>:  Where does the pythagorean theorem come from?
<bot>: The pythagorean theorem is a theorem that states that the squares of the lengths of the legs of a right triangle are equal to the squares of the lengths of the hypotenuse. The theorem is named after Pythagoras, who was a Greek mathematician and philosopher. The theorem is used in many different areas of mathematics, including geometry, algebra, and trigonometry.