相交弦定理、割线定理和切割线定理通常统称圆幂定理。它是几何论证、计算和作图的常用定理,所以是几何教学的重点之一,历来都要求学生熟练掌握。本文欲就圆幂定理的教学谈谈笔者的构想。 一、从“激趣”入手,创设良好的思维情境 对数学知识的教学,常常要从创设思维情境开始,以引起学生的认识需要,激发学生学习热情。圆幂定理的教学,可以这样引入: 同学们早就会背诵王之涣的诗——《登 Intersecting string theorem, secant theorem and cutting line theorem are usually collectively called the circle power theorem. It is a common theorem for geometrical proof, calculation and drawing. Therefore, it is one of the focuses of geometry teaching. It has always required students to master it. This article wants to talk about the author’s idea about the teaching of the circle power law. First, start with “excitement” and create a good situation for thinking Teaching mathematics knowledge often begins with the creation of a situation of thinking in order to arouse students’ understanding needs and inspire students’ enthusiasm for learning. The teaching of the circle power theorem can be introduced in this way: The students will recite the poem of Wang Zhiyu - "Deng