一、用类比法揭示二面角的概念学习二面角的概念,学生并不感到困难。当概念引入以后,再从复习平面几何中角的定义出发。使学生在新旧概念的类比中,较为深刻地理解二面角的概念很有必要。下面的表格,就是角(平面几何)和二面角概念的类比。可让学生当堂填写。 First, the analogy to reveal the concept of dihedral Learning dihedral concept, students do not feel difficult. When the concept is introduced, we start with the definition of the mid-plane geometry. It is necessary for students to understand the concept of dihedral more deeply in the analogy of old and new concepts. The following table, is the angle (plane geometry) and the concept of dihedral angle analogy. Allow students to fill in the hall.