四边形这一章中所学的概念、定理比较多 ,解四边形问题所涉及的知识也很广泛 ,因而学生在学习四边形的过程中容易产生一些错误 .下面几例是本人在教学过程中发现的几个典型错误 ,期望引起同学们的注意 .一、理解基本概念不透彻例 1　求证 :平行四边形对角线交点到一组对边的距? There are many concepts and theorems learned in the chapter of quadrilaterals. The knowledge involved in solving quadrilateral problems is also very extensive. Therefore, students are prone to errors in the process of learning quadrilaterals. The following examples are some of the findings in the teaching process. A typical mistake, I hope to arouse the attention of the students. First, understand the basic concepts are not clear Example 1 Verification: The distance between the parallelogram diagonal intersection and a set of opposite sides?