The Pythagorean theorem auxiliary tool is a teaching tool for intuitively demonstrating the Pythagorean theorem. It usually consists of three square or semi-circular modules, corresponding to the three sides of a right angled triangle. In teaching, students can verify theorems through concatenation modules: for example, by disassembling and reassembling the area of a square with side lengths a and b (a ², b ²), they can exactly fill the square with side length c (c ²), and intuitively understand that a ²+b ²=c ². Translating abstract algebraic theorems into concrete area operations helps students establish a thinking of combining numbers and shapes, and is an efficient tool for understanding the Pythagorean theorem and its extended applications.