利用辅助线求解几何问题,不但可以化繁为简,化难为易,而且常常可获得绝处逢生的奇效.然而,利用辅助线求解几何问题既是解题中常见的有效方法,也是教学中不容易为学生掌握的较难的方法.笔者经过多年的教学实践,总结并整理了圆中常见的几种辅助线的作法.现归纳成以下的顺口溜,与同行交流. The use of auxiliary lines to solve geometric problems can not only simplify the process, but also make it difficult to make it easier to understand. However, the use of auxiliary lines to solve geometric problems is not only a common and effective method in solving problems, but also in teaching. It is easy for students to grasp the more difficult method. After years of teaching practice, the author has summarized and summarized the common practice of several auxiliary lines. It is now summarized as the following jingle, and exchanges with peers.