一、教学目标1.理解圆周角的概念,掌握圆周角定理,并会用此定理进行简单的论证和计算.2.在圆周角的产生和圆周角定理的发现过程中,经历观察、类比、猜想、合作交流等数学活动,体会用运动变换的观点认识圆中的动态问题,渗透解决不确定问题的思路和方法,提高学生的发散思维能力.3.初步体会运用分类讨论、转化、完全归纳法等 First, the teaching objectives 1. Understand the concept of circular angle, grasp the circular angle theorem, and will use this theorem for a simple argument and calculation.2.While in the discovery of circular angle and the circular angle theorem, through observation, analogy, Conjecture, cooperation and exchange and other mathematical activities, understand the movement from the point of view of the circular dynamic problems, infiltration and solve the problem of uncertainty ideas and methods to improve students’ divergent thinking ability .3. Preliminary experience using the classification discussion, conversion, complete induction Law and so on