Arco de Herradura：几何与三角函数的综合应用

GeoGebra 命令及参数

1. If(zz ≤ 0, 10, zz) → u
2. Segment(D, B) → e
3. Midpoint(C, D) → K
4. Rotate(C, Max[(-ε), (((-(u - 2)) * ε) * 180 / 3.14 / (2°))], K) → C'_2
5. Circle(K, C) → f_1
6. Midpoint(C, D) → F
7. Line(F, e) → k
8. Intersect(f_1, k, 1) → L
9. Circle(L, C'_2) → g_1
10. Center(g_1) → O
11. Intersect(f_1, g_1, 1) → M
12. Mirror(M, k) → M'_1
13. Midpoint(C, D) → E
14. Segment(A, C) → d
15. Segment(E, C) → f
16. Rotate(C, Max[((-(c - 3)) * 180 / (5°)), 180°], E) → C'
17. Rotate(C, 359.91000000000014°, E) → C''
18. CircumcircleArc(C, C'', C') → g
19. Segment(C', E) → h
20. Segment(C, F) → r
21. Mirror(D, k) → D'_1
22. Intersect(f_1, g_1, 2) → N
23. Intersect(g_1, k, 2) → P
24. Angle(M, O, M'_1) → δ
25. Segment(K, C) → h_1
26. Segment(K, C'_2) → i_1
27. CircleArc(K, C'_2, C) → k_1
28. Mirror(C'_2, k) → Q
29. Segment(K, Q) → l_1
30. CircleArc(K, D, Q) → q_1
31. CircumcircleArc(Q, O, M) → t_1
32. Rotate(M, Min[δ / 2, ((u - 4) * δ / 8)], L) → R
33. Rotate(C, (-ε), K) → C'_3
34. Circle(L, C'_3) → p_1
35. CircleArc(L, M, R) → r_1
36. Segment(L, R) → j_1
37. Mirror(L, k) → L'
38. Mirror(R, k) → R'
39. Segment(L', R') → m_1
40. Mirror(L, k) → L'_1
41. Mirror(M, k) → M'
42. Mirror(R, k) → R'_1
43. Arc(Mirror[Circle[L, M], k], M', R'_1) → s_1
44. Circle(K, C) → c_2
45. Segment(T, T1) → n_1
46. Mirror(D, n_1) → D'_2
47. Mirror(B, n_1) → B'
48. Segment(D'_2, B') → e'
49. Mirror(A, n_1) → A'
50. Mirror(C, n_1) → C'_4
51. Segment(A', C'_4) → d'
52. Vector(A, B') → z
53. Translate(pic1, z) → pic1'
54. Translate(pic1, z) → pic1'_1