query: When was the Pythagorean theorem introduced?
passage: Pythagorean theorem
Although it is often argued that knowledge of the theorem predates him,[2][3] the theorem is named after the ancient Greek mathematician Pythagoras (c. 570–495 BC) as it is he who, by tradition, is credited with its first proof, although no evidence of it exists.[4][5][6] There is some evidence that Babylonian mathematicians understood the formula, although little of it indicates an application within a mathematical framework.[7][8] Mesopotamian, Indian and Chinese mathematicians all discovered the theorem independently and, in some cases, provided proofs for special cases.
passage: British flag theorem
The theorem can also be thought of as a generalisation of the Pythagorean theorem. Placing the point "P" on any of the four vertices of the rectangle yields the square of the diagonal of the rectangle being equal to the sum of the squares of the width and length of the rectangle, which is the Pythagorean theorem.