勾股定理是几何学中的一条古老而著名的定理．在数学发展史上，勾股定理的发现不仅为解决许多生产实际问题提供了有力工具，同时使数学本身向前推进了一大步．如果把勾股定理及其等效命题抽出去的话，那么数学在理论和应用上都将会裹足不前，因此有人把勾股定理的发现作为世界? Pythagorean theorem is an ancient and famous theorem in geometry. In the history of mathematics development, the discovery of the Pythagorean theorem not only provided a powerful tool for solving many practical problems in production, but also made mathematics itself a big step forward. If we extract the Pythagorean Theorem and its equivalent propositions, then mathematics will not hold forward in both theory and application. So what is the discovery of the Pythagorean theorem as a world?