背景介绍实施课程改革将近一年,桃源中学为了进一步推进课改,让老师互相学习交流,举行了“创新优质课”比赛。我作为参赛者上了“多边形的内角和”这节课。(七年级下册,华东师范大学出版社数学教材。)情景描述 Background Introduction Nearly a year after the implementation of the curriculum reform, Taoyuan Middle School held a “High Quality and Quality Training” competition to further promote curriculum reform and allow teachers to learn from each other. I used the polygon’s inner corners and the class as participants. (Grade seven grade, East China Normal University Press mathematics textbook.) Scenario Description