利用方程(组)把已知和未知联系起来,通过解方程(组)进行几何计算,是一种常用的方法,现举例说明. 1、利用勾股定理列方程例1 矩形ABCD中,对角线AC的中垂线交BC、AD于E、F. Using equations (groups) to connect known and unknown, and solving equations (groups) for geometric calculations, is a common method, which is illustrated as an example. 1. Using Pythagorean theorem column equation Example 1 Rectangular ABCD, Diagonal The vertical line of line AC intersects BC and AD is at E and F.