图形面积

等积变形与勾股定理 https://www.aliyundrive.com/s/ArpbjXxW7ie/folder/61f3adce6929a4a591194f5fa1d425ca25adfcfa folder

格点与割补 https://www.aliyundrive.com/s/ArpbjXxW7ie/folder/61f3adcfcebe72c45b8d4e8cb6115458b9fe3f7f folder

基本直线形面积公式 https://www.aliyundrive.com/s/ArpbjXxW7ie/folder/61f3adcf5d9ebb8dec12416c9b5f6a848c63fd25 folder