华师大版《数学》七年级下册中,通过“试一试”和“探索”两个环节,对“多边形内角和”给出了两种常规的求法.我们在老师的鼓励和启发下,对其求法作了进一步的探索尝试,有了新的发现,归纳如下:“多边形内角和”的求法可分为“割形”和“补形”两种思路.一、割形法通过“从一点 In the second grade of the seventh grade of “Mathematics” edition of Huashi Normal University, two common methods of “polygon internal angles” are given through the “try and try” and “exploration.” We are encouraged and inspired by the teacher. Further exploration attempts have been made to find out the method, and new discoveries have been made. They are summarized as follows: The method of “polygon inner angle and sum” can be divided into two types: “cut form” and “complement form”. From a little