很多的平面几何题都不是直接可以证明出来的,而是要借助辅助线才能证明出来。特别是中考的试题,几乎每一个平面几何题的证明都要添加辅助线帮助解答问题,有的甚至添加多条。添加辅助线是解平面几何题的难点之一,如果一道平面几何题要添加辅助线证明,只要能根据题意添加所需要的辅助线,那么这道题目就能迎刃而解。 A lot of plane geometry questions are not directly proof, but to use auxiliary lines to prove it. In particular, the senior high school entrance examination questions, almost every proof of plane geometry questions have to add aids to help solve the problem, and some even add more. Adding auxiliary line is one of the difficulties in solving plane geometry problem. If a planar geometric problem is to be added with auxiliary line, this problem can be solved as long as the required auxiliary line can be added according to the problem.