“多边形的内角和”是人教版八年级上册第十一章“三角形”一章中的一节内容,主要任务是探究多边形的内角和、外角和的计算方法,并能进行简单应用,其中蕴含了重要数学思想和方法.笔者结合多媒体课件设计讲授了此课,教学效果良好.学情:学生已经掌握了多边形的基础知识,即多边形的概念、对角线、以及正多边形的概念.教参把“多边形”与“正多边形的内角和公式”放在第一课时 “Polygonal angle and ” is a PEP eighth grade eleventh chapter “triangle ” chapter in a section, the main task is to explore the calculation of the polygon internal angle and external angle and can be carried out Simple application, which contains important mathematical ideas and methods. The author combined with the multimedia courseware designed to teach this lesson, teaching is good. Learning conditions: Students have mastered the basic knowledge of polygons, that is, the concept of polygons, diagonals, as well as regular polygons The teachings put the “polygons” and the “inner polygons and their formulas” in the first class