Pythagorean Theorem

In a right triangle the square on the hypotenuse equals the sum of the squares on the other two sides.

Specifications & Metrics

proved

known by c. 1800 BC; proved in Greek tradition c. 500 BC

Core Principles & Analysis

• Babylonian tablet Plimpton 322 lists Pythagorean triples a millennium before Pythagoras.
• Euclid's Elements gives the classic proof by equal triangles; hundreds of others exist.
• Fermat's Last Theorem is its degree-three-and-up generalization, proved only in 1994.