用韦恩图展示集合运算

GeoGebra 命令及参数

1. Circle(A, 4) → c
2. Circle(B, 4) → d
3. Circle(C, 4) → e
4. Polygon((-4.5, -9), (-4.5, 4.5), (9.5, 4.5), (9.5, -9)) → poly1, a, b, f, g