早在三国时期,我国数学家赵爽就利用“弦图”对勾股定理作出了严格而简洁的证明.弦图既是勾股定理的一种证明方法,又是数形结合思想的体现.下面,我们通过一些例子来体会一下.例1图1是用四个全等的直角三角形镶嵌而成的正方形图案.已知大正方形 As early as the Three Kingdoms period, Zhao Shuang, a mathematician in China, used string diagrams to make a rigorous and concise proof of the Pythagorean theorem. String diagrams are both a proof method of the Pythagorean theorem and a reflection of the combination of numbers and shapes. Below, we come through some examples to understand. Example 1 Figure 1 is a square pattern inlaid with four congruent right-angled triangles. Known large squares