旋转对称性：几何图形的动态演示

GeoGebra 命令及参数

1. Segment(A, B) → a
2. OrthogonalLine(A, a) → b
3. OrthogonalLine(B, a) → c
4. Point(b) → C
5. OrthogonalLine(C, b) → d
6. Intersect(c, d) → D
7. Polygon(C, D, B, A) → poly1, c_1, d_1, b_1, a_1
8. Segment(C, B) → e
9. Segment(D, A) → f
10. Intersect(e, f) → E
11. Polygon(F, G, 4) → poly2, f_1, g, h, i, H, I
12. Segment(I, G) → j
13. Segment(H, F) → k
14. Intersect(j, k) → J
15. Segment(K, L) → l
16. Circle(K, L) → p
17. Point(p) → M
18. Segment(K, M) → m
19. Line(M, l) → n
20. Line(L, m) → q
21. Intersect(n, q) → N
22. Segment(M, L) → r
23. Segment(N, K) → s
24. Intersect(r, s) → O
25. Polygon(M, N, L, K) → poly3, m_1, n_1, l_1, k_1
26. Rotate(C, (-α), E) → C'
27. Rotate(D, (-α), E) → D'
28. Rotate(B, (-α), E) → B'
29. Rotate(A, (-α), E) → A'
30. Polygon(C', D', B', A') → Rectangle, c', d', b', a'
31. Rotate(M, (-α), O) → M'
32. Rotate(N, (-α), O) → N'
33. Rotate(L, (-α), O) → L'
34. Rotate(K, (-α), O) → K'
35. Polygon(M', N', L', K') → Rhombus, m', n', l', k'
36. Segment(P, Q) → t
37. Segment(P, R) → e_1
38. Line(Q, e_1) → g_1
39. Line(R, t) → h_1
40. Intersect(g_1, h_1) → S
41. Polygon(P, R, S, Q) → poly4, p_1, r_1, s_1, q_1
42. Segment(R, Q) → i_1
43. Segment(S, P) → j_1
44. Intersect(i_1, j_1) → T
45. Rotate(P, (-α), T) → P'
46. Rotate(R, (-α), T) → R'
47. Rotate(S, (-α), T) → S'
48. Rotate(Q, (-α), T) → Q'
49. Polygon(P', R', S', Q') → Parallelogram, p', r', s', q'
50. Segment(U, V) → t_1
51. Segment(U, W) → a_2
52. Line(W, t_1) → b_2
53. Point(b_2) → Z
54. Segment(Z, V) → c_2
55. Polygon(U, V, Z, W) → poly5, u, v, z, w
56. Segment(W, V) → d_2
57. Segment(Z, U) → e_2
58. Intersect(d_2, e_2) → A_1
59. Rotate(U, (-α), A_1) → U'
60. Rotate(V, (-α), A_1) → V'
61. Rotate(Z, (-α), A_1) → Z'
62. Rotate(W, (-α), A_1) → W'
63. Polygon(U', V', Z', W') → Trapezoid, u', v', z', w'
64. Line(B_1, C_1) → f_2
65. Mirror(D_1, f_2) → E_1
66. Polygon(D_1, B_1, E_1, C_1) → poly6, d_3, b_3, e_3, c_3
67. Segment(D_1, E_1) → g_2
68. Intersect(f_2, g_2) → F_1
69. Rotate(D_1, (-α), F_1) → G_1
70. Rotate(B_1, (-α), F_1) → H_1
71. Rotate(E_1, (-α), F_1) → I_1
72. Rotate(C_1, (-α), F_1) → J_1
73. Polygon(G_1, H_1, I_1, J_1) → Kite, g_3, h_2, i_2, j_2
74. Rotate(poly2, (-α), J) → Square
75. Line(K_1, L_1) → k_2
76. Circle(M_1, N_1) → Circle
77. Rotate(N_1, α, M_1) → O_1
78. Angle(N_1, M_1, O_1) → β
79. Polygon(P_1, Q_1, 5) → poly7, l_2, m_2, n_2, p_2, q_2, R_1, S_1, T_1
80. Line(P_1, T_1) → r_2
81. Line(R_1, S_1) → s_2
82. Line(S_1, T_1) → t_2
83. Line(Q_1, P_1) → f_3
84. Line(R_1, Q_1) → h_3
85. Intersect(s_2, r_2) → U_1
86. Intersect(t_2, f_3) → V_1
87. Intersect(r_2, h_3) → W_1
88. Intersect(f_3, s_2) → Z_1
89. Intersect(h_3, t_2) → A_2
90. Intersect(r_2, t_2) → B_2
91. Intersect(f_3, r_2) → C_2
92. Intersect(h_3, f_3) → D_2
93. Intersect(s_2, h_3) → E_2
94. Intersect(s_2, t_2) → F_2
95. Polygon(U_1, B_2, V_1, C_2, W_1, D_2, Z_1, E_2, G_2, F_2) → poly8, u_1, f_4, b_4, v_1, c_4, w_1, d_4, z_1, e_4, g_4
96. Line(H_2, I_2) → i_3
97. Mirror(J_2, i_3) → O_2
98. Mirror(K_2, i_3) → P_2
99. Mirror(L_2, i_3) → Q_2
100. Mirror(M_2, i_3) → R_2
101. Mirror(N_2, i_3) → S_2
102. Polygon(J_2, O_2, P_2, Q_2, R_2, S_2, N_2, M_2, L_2, T_2) → poly9, j_3, t_3, o_2, p_3, q_3, r_3, s_3, n_3, m_3, l_3