特殊等腰三角形与平行四边形的动态几何演示（GoGeometry 第43号）

GeoGebra 命令及参数

1. Rotate(B, (80 * π / 180), A) → B'
2. Angle(B, A, B') → α
3. Rotate(A, (-80 * π / 180), B) → A'
4. Angle(A, B, A') → β
5. Segment(A, B) → f
6. Ray(A, B') → g
7. Ray(B, A') → h
8. Intersect(g, h) → C
9. Segment(A, C) → i
10. Segment(C, B) → j
11. Rotate(B, π / 3, C) → B'_1
12. Segment(B, B'_1) → k
13. Segment(C, B'_1) → l
14. Rotate(B, π / 9, C) → B'_2
15. Angle(B, C, B'_2) → γ
16. Rotate(B'_2, π / 9, C) → D
17. Angle(B'_2, C, D) → δ
18. Ray(C, B'_2) → m
19. Ray(C, D) → n
20. Intersect(k, m) → E
21. Intersect(k, n) → F
22. Circle(C, (0.2 * j)) → c
23. Intersect(c, j, 1) → G
24. Intersect(c, i, 1) → H
25. Segment(C, E) → p
26. Segment(C, F) → q
27. Intersect(c, p, 1) → I
28. Intersect(c, q, 1) → J
29. Circle(B, A) → d
30. Intersect(d, i) → K, L
31. Intersect(d, j, 1) → M
32. LineBisector(i) → r
33. Intersect(r, j) → N
34. Dilate(A, If[0 < a ≤ 1, 1 - a, 0], B) → A'_1
35. Dilate(C, If[0 < a ≤ 1, 1 - a, 0], B) → H'
36. Segment(C, H') → t
37. Rotate(C, If[1 < a ≤ 2, (((-(a - 1)) * 20) * π / 180), (-20 * π / 180)], C) → C'
38. Rotate(H', If[1 < a ≤ 2, (((-(a - 1)) * 20) * π / 180), (-20 * π / 180)], C) → H''
39. Segment(C', H'') → t'
40. Dilate(A, If[2 < a ≤ 3, 3 - a, 0], B) → A'_2
41. Segment(A, A'_2) → s
42. Polygon(A, B, C) → poly1, c_1, a_1, b
43. Rotate(C, If[3 < a ≤ 4, ((a - 3) * π / 3), π / 3], C) → C'_1
44. Rotate(H', If[3 < a ≤ 4, ((a - 3) * π / 3), π / 3], C) → H''_1
45. Segment(C'_1, H''_1) → t'_1
46. Rotate(C, If[4 < a ≤ 5, ((-(a - 4)) * π / 3), ((-π)) / 3], B) → C'_2
47. Rotate(H', If[4 < a ≤ 5, ((-(a - 4)) * π / 3), ((-π)) / 3], B) → H''_2
48. Segment(C'_2, H''_2) → t'_2
49. Polygon(C, B, B'_1) → poly2, b'_1, c_2, b_1
50. Intersect(c, l) → O,
51. Dilate(C, If[5 < a ≤ 6, 6 - a, 0], E) → C'_3
52. Dilate(C, If[5 < a ≤ 6, 6 - a, 0], F) → C'_4
53. Segment(C, C'_3) → e
54. Segment(C, C'_4) → f_1
55. CircleSector(C, J, O) → d_1
56. Rotate(d_1, If[7 < a ≤ 8, (((-(a - 7)) * 20) * π / 180), (-20 * π / 180)], C) → e_1
57. Rotate(e_1, If[9 < a ≤ 10, (((-(a - 9)) * 20) * π / 180), (-20 * π / 180)], C) → g_1
58. Rotate(g_1, If[11 < a ≤ 12, (((-(a - 11)) * 20) * π / 180), (-20 * π / 180)], C) → h_1
59. Midpoint(C, A) → P
60. Dilate(C, If[12.5 < a ≤ 13.5, 13.5 - a, 0], P) → C'_5
61. Vector(C, C'_5) → u
62. Translate(h_1, u) → k_1
63. Rotate(k_1, If[13.5 < a ≤ 14.5, (((a - 13.5) * 160) * π / 180), (160 * π / 180)], P) → p_1
64. Dilate(A, If[14.5 < a ≤ 15.5, 15.5 - a, 0], N) → A'_3
65. Segment(A, A'_3) → i_1
66. Dilate(P, If[15.5 < a ≤ 16.5, 16.5 - a, 0], A) → P'
67. Vector(P, P') → v
68. Translate(p_1, v) → q_1
69. Rotate(A, If[16.5 < a ≤ 17.5, (((-(a - 16.5)) * 80) * π / 180), (-80 * π / 180)], B) → A'_4
70. Segment(B, A'_4) → j_1
71. CircleArc(B, A'_4, A) → r_1
72. Angle(L, B, A) → ε
73. Segment(B, L) → l_1
74. Polygon(A, C, N) → poly3, n_1, a_2, c_3
75. Polygon(A, N, B) → poly4, b_2, a_3, n_2
76. Dilate(A, If[18.5 < a ≤ 19.5, 19.5 - a, 0], L) → A'_5
77. Vector(A, A'_5) → w
78. Segment(A, A'_5) → m_1
79. Dilate(L, If[19.5 < a ≤ 20.5, 20.5 - a, 0], M) → L'
80. Vector(L, L') → u_1
81. Translate(A, u_1) → A'_6
82. Translate(A'_5, u_1) → Q
83. Segment(A'_6, Q) → s_1
84. Rotate(A'_6, If[20.5 < a ≤ 21.5, (((-(a - 20.5)) * 160) * π / 180), (-160 * π / 180)], M) → R
85. Rotate(Q, If[20.5 < a ≤ 21.5, (((-(a - 20.5)) * 160) * π / 180), (-160 * π / 180)], M) → Q'
86. Segment(R, Q') → t_1