Zhao Shuang's Xuan Tu: A Classic Geometric Proof of the Pythagorean Theorem

This applet demonstrates 'Xuan Tu' (the Chord Diagram), created by the ancient Chinese mathematician Zhao Shuang, to visually prove the Pythagorean theorem. By constructing four congruent right-angled triangles and a central small square, they are assembled into a larger square. Using area relationships, the area of the large square equals the sum of the areas of the four triangles and the central