动画演示圆与切线关系

GeoGebra 命令及参数

1. Circle(A, B) → c
2. Distance(A, B) → b
3. PointIn(d) → C
4. Tangent(C, c) → a, e
5. Intersect(c, a, 1) → D
6. Intersect(c, e, 1) → E
7. Point(a) → F
8. Point(e) → G
9. Angle(F, D, A) → α
10. Angle(A, E, G) → β
11. Ray(C, D) → f
12. Ray(C, E) → g
13. CircleArc(A, D, E) → h
14. Point(h) → H
15. CircleArc(A, D, H) → k
16. Point(k) → I
17. Ray(C, I) → i
18. Ray(C, H) → j
19. CircleArc(A, H, E) → p
20. Intersect(c, j, 1) → J
21. Intersect(c, i, 1) → K
22. CircleArc(A, H, I) → q
23. Point(q) → L
24. CircleArc(A, K, J) → r
25. Point(r) → M
26. CircleArc(A, I, H) → s
27. CircleArc(A, J, K) → t
28. CircleArc(A, K, I) → c_1
29. CircleArc(A, H, J) → d_1
30. Segment(L, I) → l
31. Segment(L, H) → m
32. Segment(M, J) → n
33. Segment(M, K) → a_1
34. Segment(A, D) → b_1
35. Segment(A, E) → e_1
36. Circle(L, (0.25 * Distance[A, B])) → f_1
37. Circle(M, (0.25 * Distance[A, B])) → g_1
38. Intersect(l, i) → O
39. Intersect(f_1, c, 1) → Q
40. Intersect(f_1, l, 1) → P
41. Intersect(f_1, m, 1) → R
42. Intersect(g_1, n, 1) → N
43. Intersect(g_1, a_1, 1) → S
44. CircleSector(M, N, S) → h_1
45. CircleSector(L, P, R) → k_1
46. Dilate(M, If[0 < o ≤ 1, 1 - o, 0], L) → M'
47. Vector(M, M') → u
48. Translate(h_1, u) → p_1
49. Translate(S, u) → S'
50. Angle(R, L, S') → γ
51. Rotate(p_1, If[1 < o ≤ 2, ((-(o - 1)) * γ), (-γ)], L) → q_1
52. Translate(N, u) → N'
53. Rotate(N', (-γ), L) → N''
54. CircleSector(L, P, N'') → r_1
55. Dilate(L, If[3 < o ≤ 4, 4 - o, 0], C) → L'
56. Vector(L, L') → v
57. Translate(r_1, v) → s_1
58. Translate(P, v) → P'
59. Circle(C, (0.25 * Distance[A, B])) → t_1
60. Intersect(t_1, i, 1) → T
61. Angle(P', C, T) → δ
62. Rotate(s_1, If[4 < o ≤ 5, ((o - 4) * δ), δ], C) → c_2