用面积法证明平面几何问题是个年轻而又古老的问题.说它年轻,是因为不少的学生还不熟悉它的方法;讲它古老,是因为二千多年前,我国古代数学家,就运用了面积法给出了勾股定理的证明.堪称它出奇制胜,“奇”在何处? The use of the area method to prove the problem of plane geometry is a young and ancient problem. It is young because many students are not familiar with its methods; it is ancient because two thousand years ago, ancient mathematicians in our country Using the area method gives a proof of the Pythagorean theorem. It can be said that it is surprisingly successful. Where is “odd”?