在实际教学中,发现不少同学在解(证)几何问题时,思维受阻的一个重要原因是不会正确的作出辅助线,对如何作辅助线认识朦胧,目标不明,仅凭直觉而缺少理性分析.这里,我们来谈谈根据数学思想并结合题目特点来构造辅助线,以求探寻常用辅助线的理论依据.一、根据模型思想,构造基本图 In practical teaching, I discovered that when students solve problems in geometry, one of the important reasons for the obstruction of thinking is that they do not make correct auxiliary lines, they know how to make auxiliary lines, their goals are not clear, and they only rely on intuition and lack rationality. Analysis. Here, we talk about constructing auxiliary lines based on mathematics ideas and combining the features of the topics, in order to explore the theoretical basis for commonly used auxiliary lines. First, according to the model idea, construct basic charts.