本文要讨论的是1989年第六届巴尔干数学竞赛中的一道几何证明题,笔者认为这道题目是值得一做的好题,波利亚在其著作“怎样解题”中说到好题目和坏题目,好题目是能够让做题目的人对之感兴趣并愿意花时间去做的,体现重要数学思想方法的,可以从中获得成功喜悦的题目.笔者的目的是围绕这道题来设计一堂以变式教学为视角的探究型课.1.题目题目直线2分别交△ABC的边AB、AC This article is going to discuss a geometric proof in the Sixth Balkan Mathematical Contest in 1989. I think this topic is a good question worth doing. Polia said in his book How to Solve Problems Problems and bad topics, the good topic is to make the subject people are interested and willing to take the time to do, reflect the important mathematical ideas and methods, you can get the joy of success from the subject.The author’s purpose is to around this issue Design a variant teaching to explore the perspective of the lesson .1 subject line 2 respectively intersect △ ABC AB, AC