韦恩图的集合交并示意：用圆与几何构造刻画区域关系

GeoGebra 命令及参数

1. Circle(A, B) → c
2. Circle(B, A) → d
3. Segment(A, B) → f
4. Circle(A, f + 0.6) → e
5. Circle(B, f + 0.6) → g
6. OrthogonalLine(A, f) → h
7. Intersect(e, h) → C, D
8. Intersect(c, d) → E, F, ,
9. Tangent(D, e) → i,
10. Tangent(C, e) → j,
11. Line(A, B) → k
12. Intersect(e, k) → G, H
13. Intersect(g, k) → I, J
14. OrthogonalLine(G, f) → l
15. OrthogonalLine(J, k) → m
16. Intersect(m, i) → K
17. Intersect(l, i) → L
18. Intersect(j, l) → M
19. Intersect(m, j) → N
20. Polygon(M, N, K, L) → q1, m_1, n, k_1, l_1
21. CircleSector(B, E, F) → p
22. CircleSector(A, F, E) → q
23. Midpoint(B, K) → O
24. Midpoint(O, K) → P
25. Circle(A, B) → r
26. Circle(B, A) → s
27. Point(r) → Q
28. Point(s) → R