正方形的旋转对称性演示 by youngcar

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. Segment(C, B) → e
8. Segment(D, A) → f
9. Intersect(e, f) → E
10. Polygon(F, G, 4) → poly2, f_1, g, h, i, H, I
11. Segment(I, G) → j
12. Segment(H, F) → k
13. Intersect(j, k) → J
14. Segment(K, L) → l
15. Circle(K, L) → p
16. Point(p) → M
17. Segment(K, M) → m
18. Line(M, l) → n
19. Line(L, m) → q
20. Intersect(n, q) → N
21. Segment(M, L) → r
22. Segment(N, K) → s
23. Intersect(r, s) → O
24. Rotate(C, (-α), E) → C'
25. Rotate(D, (-α), E) → D'
26. Rotate(B, (-α), E) → B'
27. Rotate(A, (-α), E) → A'
28. Polygon(C', D', B', A') → poly1', c', d', b', a'
29. Rotate(M, (-α), O) → M'
30. Rotate(N, (-α), O) → N'
31. Rotate(L, (-α), O) → L'
32. Rotate(K, (-α), O) → K'
33. Polygon(M', N', L', K') → poly3', m', n', l', k'
34. Segment(P, Q) → t
35. Segment(P, R) → e_1
36. Line(Q, e_1) → g_1
37. Line(R, t) → h_1
38. Intersect(g_1, h_1) → S
39. Segment(R, Q) → i_1
40. Segment(S, P) → j_1
41. Intersect(i_1, j_1) → T
42. Rotate(P, (-α), T) → P'
43. Rotate(R, (-α), T) → R'
44. Rotate(S, (-α), T) → S'
45. Rotate(Q, (-α), T) → Q'
46. Polygon(P', R', S', Q') → poly4', p', r', s', q'
47. Segment(U, V) → t_1
48. Line(W, t_1) → b_2
49. Point(b_2) → Z
50. Segment(W, V) → d_2
51. Segment(Z, U) → e_2
52. Intersect(d_2, e_2) → A_1
53. Rotate(U, (-α), A_1) → U'
54. Rotate(V, (-α), A_1) → V'
55. Rotate(Z, (-α), A_1) → Z'
56. Rotate(W, (-α), A_1) → W'
57. Line(B_1, C_1) → f_2
58. Mirror(D_1, f_2) → E_1
59. Segment(D_1, E_1) → g_2
60. Intersect(f_2, g_2) → F_1
61. Rotate(D_1, (-α), F_1) → G_1
62. Rotate(B_1, (-α), F_1) → H_1
63. Rotate(E_1, (-α), F_1) → I_1
64. Rotate(C_1, (-α), F_1) → J_1
65. Polygon(G_1, H_1, I_1, J_1) → poly6', g_3, h_2, i_2, j_2
66. Rotate(poly2, (-α), J) → poly2'
67. Intersect(h, i) → L_1
68. PointIn(poly2') → K_1