拿破仑运动动态演示

拿破仑运动动态演示
几何画板及绘图内容加载中,请稍等……
2016-05-22 03:51
①本范例动态演示拿破仑定理,通过动态图形展示三个等边三角形的中心构成的三角形始终为等边三角形这一现象;②涉及的核心数学概念包括三角形、等边三角形、中心点、旋转、缩放等几何变换;③作图要点——从下方『构造摘要』提炼用到了 Polygon(多边形)、Segment(线段)、Rotate(旋转)、Midpoint(中点)、Min(最小值)、Dilate(缩放)、Intersect(交点)等 GeoGebra 命令/对象;④适合高中及以上数学学习者,用于理解几何变换与定理证明的直观方法。

GeoGebra 命令及参数

  1. Polygon(A, B, C) → poly1, c, a, b
  2. Polygon(C, B, 3) → poly2, d, e, f, D
  3. Polygon(A, C, 3) → poly3, g, h, i, E
  4. Polygon(B, A, 3) → poly4, j, k, l, F
  5. Segment(A, B) → m
  6. Segment(B, C) → n
  7. Segment(C, A) → p
  8. Rotate(B, If[0 < o ≤ 1, (o * π / 3), 1.0471975511965976], B) → B'
  9. Rotate(C, If[0 < o ≤ 1, ((-o) * π / 3), -1.0472], B) → C'
  10. Segment(B', C') → n'
  11. Rotate(B, If[1 < o ≤ 2, ((o - 1) * π / 3), 1.0472], C) → B'_1
  12. Rotate(C, If[0 < o ≤ 1, (o * π / 3), 1.0471975511965976], C) → C'_1
  13. Segment(B'_1, C'_1) → n'_1
  14. Rotate(C, If[2 < o ≤ 3, ((-(o - 2)) * π / 3), -1.0471975511965976], C) → C'_2
  15. Rotate(A, If[2 < o ≤ 3, ((-(o - 2)) * π / 3), -1.0471975511965976], C) → A'
  16. Segment(C'_2, A') → p'
  17. Rotate(C, If[3 < o ≤ 4, ((o - 3) * π / 3), 1.0471975511965976], A) → C'_3
  18. Rotate(A, If[3 < o ≤ 4, ((o - 3) * π / 3), 1.0471975511965976], A) → A'_1
  19. Segment(C'_3, A'_1) → p'_1
  20. Rotate(A, If[4 < o ≤ 5, ((-(o - 4)) * π / 3), -1.0471975511965976], A) → A'_2
  21. Rotate(B, If[4 < o ≤ 5, ((-(o - 4)) * π / 3), -1.0471975511965976], A) → B'_2
  22. Segment(A'_2, B'_2) → m'
  23. Rotate(A, If[5 < o ≤ 6, ((o - 5) * π / 3), 1.0471975511965976], B) → A'_3
  24. Rotate(B, If[5 < o ≤ 6, ((o - 5) * π / 3), 1.0471975511965976], B) → B'_3
  25. Segment(A'_3, B'_3) → m'_1
  26. Midpoint(p) → G
  27. Midpoint(n) → H
  28. Midpoint(m) → I
  29. Segment(D, H) → q
  30. Segment(E, G) → r
  31. Segment(F, I) → s
  32. Min(list1) → t
  33. Segment(H, B) → a_1
  34. Segment(C, G) → b_1
  35. Segment(A, I) → c_1
  36. Dilate(D, If[6 < o ≤ 7, 7 - o, 0], H) → D'
  37. Segment(D, D') → d_1
  38. Dilate(E, If[6 < o ≤ 7, 7 - o, 0], G) → E'
  39. Segment(E, E') → e_1
  40. Dilate(F, If[6 < o ≤ 7, 7 - o, 0], I) → F'
  41. Segment(F, F') → f_1
  42. Rotate(H, If[7.5 < o ≤ 8.5, ((o - 7.5) * π), 3.141592653589793], H) → H'
  43. Rotate(B, If[7.5 < o ≤ 8.5, ((o - 7.5) * π), 3.141592653589793], H) → B'_4
  44. Segment(H', B'_4) → g_1
  45. Rotate(C, If[7.5 < o ≤ 8.5, ((o - 7.5) * π), 3.141592653589793], G) → C'_4
  46. Rotate(G, If[7.5 < o ≤ 8.5, ((o - 7.5) * π), 3.141592653589793], G) → G'
  47. Segment(C'_4, G') → h_1
  48. Rotate(A, If[7.5 < o ≤ 8.5, ((o - 7.5) * π), 3.141592653589793], I) → A'_4
  49. Rotate(I, If[7.5 < o ≤ 8.5, ((o - 7.5) * π), 3.141592653589793], I) → I'
  50. Segment(A'_4, I') → i_1
  51. Midpoint(p') → J
  52. Midpoint(m') → K
  53. Midpoint(n') → L
  54. Segment(J, C) → j_1
  55. Segment(B, L) → k_1
  56. Segment(A, K) → l_1
  57. Dilate(A, If[9 < o ≤ 10, 10 - o, 0], J) → A'_5
  58. Segment(A, A'_5) → m_1
  59. Dilate(C, If[9 < o ≤ 10, 10 - o, 0], L) → C'_5
  60. Segment(C, C'_5) → n_1
  61. Dilate(B, If[9 < o ≤ 10, 10 - o, 0], K) → B'_5
  62. Segment(B, B'_5) → p_1
  63. Rotate(B, If[10.5 < o ≤ 11.5, ((o - 10.5) * π), 3.141592653589793], L) → B'_6
  64. Rotate(L, If[10.5 < o ≤ 11.5, ((o - 11.5) * π), 3.141592653589793], L) → L'
  65. Segment(B'_6, L') → q_1
  66. Rotate(J, If[10.5 < o ≤ 11.5, ((o - 10.5) * π), 3.141592653589793], J) → J'
  67. Rotate(C, If[10.5 < o ≤ 11.5, ((o - 10.5) * π), 3.141592653589793], J) → C'_6
  68. Segment(J', C'_6) → r_1
  69. Rotate(A, If[10.5 < o ≤ 11.5, ((o - 10.5) * π), 3.141592653589793], K) → A'_6
  70. Rotate(K, If[10.5 < o ≤ 11.5, ((o - 10.5) * π), 3.141592653589793], K) → K'
  71. Segment(A'_6, K') → s_1
  72. Intersect(e_1, m_1) → M
  73. Intersect(f_1, p_1) → N
  74. Intersect(d_1, n_1) → O
  75. Dilate(N, If[12 < o ≤ 13, 13 - o, 0], O) → N'
  76. Segment(N, N') → t_1
  77. Rotate(N, If[13 < o ≤ 14, ((-(o - 13)) * π / 3), -1.0472], O) → N'_1
  78. Rotate(N', If[13 < o ≤ 14, ((o - 13) * π / 3), 1.0471975511965976], O) → N''
  79. Segment(N'_1, N'') → a_2
  80. Rotate(N, If[14 < o ≤ 15, ((o - 14) * π / 3), 1.0471975511965976], N) → N'_2
  81. Rotate(N', If[14 < o ≤ 15, ((o - 14) * π / 3), 1.0471975511965976], N) → N''_1
  82. Segment(N'_2, N''_1) → b_2
  83. Polygon(N, O, M) → poly5, m_2, n_2, o_1