在解初中数学几何训练题或竞赛题时,经常遇到解求阴影面积的问题,而解一些求阴影面积的问题用一般的方法是比较麻烦的.如果用设元,建立方程组来解,将会简便得多.下面举例说明. When solving junior mathematics mathematics geometry training questions or competition questions, the problem of solving the shadow area is often encountered, and solving some of the problem of finding the shadow area is more troublesome with the general method. If you use the setting element, establish a system of equations to solve, It will be much simpler. Here is an example.