教学实践证明，抓住涉及面广，思路开阔的典型题目，引导学生多角度思考，是提高学生综合运用知识能力的有效途径笔者在复习二面角这部分内容时精选了一个例题，在教师的启发引导下，由学生思考讨论，这样在活跃的研究气氛中，学生通过多角度、多层次的思考，探讨出解决题目的 Teaching practice proves that seizing a wide range of topics and broadening the typical problems and guiding students to think in multiple ways is an effective way to improve the students’ comprehensive use of knowledge. The author selected an example when reviewing this part of the dihedral angle. Under the guidance of the enlightenment, the students think and discuss, so that in an active research atmosphere, the students explore the problem solving through multi-angle and multi-level thinking.