两切线夹角与圆内角关系的动态几何演示

GeoGebra 命令及参数

1. Circle(A, B) → c
2. Segment(A, B) → f
3. PointIn(b) → C
4. Semicircle(A, C) → d
5. Semicircle(C, A) → e
6. Intersect(c, d, 1) → D
7. Intersect(c, e, 1) → E
8. Segment(C, D) → g
9. Segment(C, E) → h
10. CircleArc(A, E, D) → k
11. Segment(D, E) → i
12. Midpoint(i) → G
13. LineBisector(i) → j
14. Intersect(k, j, 1) → F
15. CircleArc(A, E, F) → p
16. Point(p) → H
17. Line(C, H) → l
18. Segment(F, D) → m
19. Segment(F, E) → n
20. Segment(H, G) → q
21. Segment(H, E) → r
22. Segment(H, D) → s
23. Intersect(l, i) → I
24. Angle(D, H, G) → α
25. Angle(I, H, E) → β
26. Dilate(C, If[0 < a ≤ 1, 1 - a, 0], D) → C'
27. Dilate(C, If[0 < a ≤ 1, 1 - a, 0], E) → C'_1
28. Segment(C, C') → t
29. Segment(C, C'_1) → f_1
30. Line(C, D) → g_1
31. Line(C, E) → h_1
32. Circle(D, 3) → c_1
33. Circle(E, 3) → d_1
34. Intersect(c_1, g_1, 2) → J
35. Intersect(d_1, h_1, 2) → K
36. Ray(D, J) → i_1
37. Ray(E, K) → j_1
38. Angle(J, D, A) → γ
39. Angle(A, E, K) → δ
40. Dilate(A, If[1 < a ≤ 2, 2 - a, 0], D) → A'
41. Dilate(A, If[1 < a ≤ 2, 2 - a, 0], E) → A'_1
42. Segment(A, A') → k_1
43. Segment(A, A'_1) → l_1
44. Dilate(D, If[2 < a ≤ 3, 3 - a, 0], G) → D'
45. Segment(D, D') → m_1
46. Dilate(G, If[3 < a ≤ 4, 4 - a, 0], E) → G'
47. Segment(G, G') → n_1
48. Rotate(D, If[4 < a ≤ 5, ((a - 4) * π), π], G) → D'_1
49. Rotate(D', If[4 < a ≤ 5, ((a - 4) * π), π], G) → D''
50. Segment(D'_1, D'') → p_1
51. Circle(H, (0.4 * q)) → e_1
52. Intersect(e_1, s) → L,
53. Dilate(H, If[5 < a ≤ 6, 6 - a, 0], E) → H'
54. Dilate(H, If[5 < a ≤ 6, 6 - a, 0], D) → H'_1
55. Dilate(H, If[5 < a ≤ 6, 6 - a, 0], G) → H'_2
56. Segment(H, H'_1) → q_1
57. Segment(H, H'_2) → r_1
58. Segment(H, H') → s_1
59. Dilate(C, If[6 < a ≤ 7, 7 - a, 0], I) → C'_2
60. Segment(C, C'_2) → t_1
61. Rotate(L, If[7 < a ≤ 8, ((a - 7) * α), α], H) → L'
62. CircleSector(H, L, L') → c_2
63. Midpoint(H, C) → M
64. Dilate(H, If[8 < a ≤ 9, 9 - a, 0], M) → H'_3
65. Vector(H, H'_3) → u
66. Translate(c_2, u) → d_2
67. Line(M, s_1) → a_1
68. Line(M, r_1) → b_1
69. Intersect(b_1, k_1) → N
70. Intersect(f_1, a_1) → O
71. Angle(N, M, O) → ε
72. Rotate(d_2, If[9 < a ≤ 10, ((a - 9) * ε), ε], M) → e_2
73. Dilate(M, If[10 < a ≤ 11, 11 - a, 0], H) → M'
74. Vector(M, M') → v
75. Translate(e_2, v) → f_2