from Wiktionary, Creative Commons Attribution/Share-Alike License
- proper n. A mathematical theorem which states that the square of the length of the hypotenuse of a right triangle is equal to the sum of the squares of those of the two other sides.
- proper n. A generalization of the Pythagorean theorem for Euclidean triangles to Hilbert spaces
Named after Pythagoras, from Ancient Greek Πυθαγόρας (Pythagoras), Greek mathematician and philosopher who by tradition is credited with theorem’s discovery and proof. (Wiktionary)