等腰三角形中辅助线的作法浅析

An Analysis of How to Draw Auxiliary Lines in Problems Concerning Isosceles Triangles

笔者通过对近五年云南中考数学试卷研究总结发现,三角形在空间与图形模块中占有绝对的主导地位。而卷面几何题直观感觉就是题目的精简,图形的简单化。在这条件完全不够,图形表象也不突出的情况下,很多学生只能望题兴叹。如果不会遇水造"桥",那只有顺着"河"走,绕来绕去。出题人造河,解题人造桥,才是最完美的解题规律。

Through a study and summarization of mathematics tests in recent five years＇ senior high school entrance examina- tions of Yunnan, the writer found that triangles occupy an abso- lutely dominant position in problems involving space and graph- ics. The intuitive sense of geometry problems is the simplification of problems and graphics. Under the situation of insufficient con- ditions and subtle graphics, many students don＇t know what to do. Without a ＂bridge＂, some people will detour by walking along the ＂river＂. Test-makers build rivers, while candidates build bridges, and this is the very law of problem-solving.