鱼的概率演示（梯形几何与三角函数概率问题）

GeoGebra 命令及参数

1. Polygon(A, B, C, D) → poly1, a, b, c, d
2. Point(a) → E
3. Point(b) → F
4. Segment(E, G) → e
5. Segment(F, H) → f
6. Intersect(f, e) → I
7. Polygon(B, F, I, E) → poly2, b_1, f_1, i_1, e_1
8. Polygon(F, I, G, C) → poly3, f_2, i_2, g_1, c_1
9. Polygon(E, I, H, A) → poly4, e_2, i_3, h_1, a_1
10. Polygon(I, G, D, H) → poly5, i_4, g_2, d_1, h_2
11. Midpoint(B, E) → J
12. Midpoint(E, A) → L
13. Midpoint(B, F) → M
14. Midpoint(F, C) → N
15. Segment(B, I) → k
16. Segment(E, F) → l
17. Segment(I, C) → m
18. Segment(F, G) → n
19. Segment(E, H) → p
20. Segment(I, A) → q
21. Segment(I, D) → r
22. Segment(G, H) → s
23. Intersect(k, l) → O
24. Intersect(n, m) → P
25. Intersect(p, q) → Q
26. Intersect(r, s) → R