Shearer 动态几何演示

Shearer 动态几何演示
几何画板及绘图内容加载中,请稍等……
2019-12-16 23:52
①这个范例动态演示了一个由Catriona Shearer提出的问题中的几何图形变换现象;②涉及的核心数学概念包括矩形、代数、二项分布、最大公约数与最小公倍数、四边形、组合数学;③作图要点提炼自GeoGebra命令:Intersect(交点)、Rotate(旋转)、Ray(射线)、OrthogonalLine(垂线)、Polygon(多边形)、Distance(距离)、Circle(圆)、Segment(线段)、Angle(角度)、Dilate(缩放)、Vector(向量)、Translate(平移)、CircleSector(扇形);④适合高中及以上数学学习者,用于理解复杂几何构造与动态变化过程。

GeoGebra 命令及参数

  1. Intersect(xAxis, yAxis) → A
  2. Rotate(F, (-(15°)), A) → F'_1
  3. Ray(A, F'_1) → f
  4. OrthogonalLine(F'_1, yAxis) → g
  5. Intersect(g, yAxis) → H
  6. OrthogonalLine(D, yAxis) → h
  7. Intersect(h, yAxis) → I
  8. Polygon(A, B, D, I) → q1, a_1, b_1, d, i
  9. Distance(A, F'_1) → c
  10. Circle(D, Distance[D, B]) → e
  11. Segment(H, A) → q
  12. Segment(A, B) → r
  13. Segment(H, F'_1) → s
  14. Segment(F'_1, E) → t
  15. Segment(I, D) → f_1
  16. Segment(D, B) → g_1
  17. Segment(A, D) → j
  18. Polygon(A, D, 3) → poly1, k, l, m, C
  19. Circle(D, s) → p
  20. Rotate(D, (-(15°)), C) → D'
  21. Rotate(D, 75°, C) → D'_1
  22. Segment(F'_1, D'_1) → n
  23. Ray(F'_1, D') → b
  24. OrthogonalLine(D, b) → h_1
  25. Intersect(h_1, b) → J
  26. OrthogonalLine(D, h_1) → i_1
  27. Intersect(i_1, n) → K
  28. Segment(F'_1, J) → j_1
  29. Segment(J, D) → k_1
  30. Segment(D, K) → l_1
  31. Segment(K, F'_1) → m_1
  32. Angle(K, F'_1, H) → α
  33. Angle(j_1, f_1) → β
  34. Rotate(A, If[0 < o ≤ 1, ((-o) * π / 3), ((-π)) / 3], D) → A'
  35. Rotate(B, If[0 < o ≤ 1, ((-o) * π / 3), ((-π)) / 3], D) → B'
  36. Rotate(D, If[0 < o ≤ 1, ((-o) * π / 3), ((-π)) / 3], D) → D'_2
  37. Rotate(I, If[0 < o ≤ 1, ((-o) * π / 3), ((-π)) / 3], D) → I'
  38. Polygon(A', B', D'_2, I') → q1', a', b', d'_2, i'
  39. Dilate(J, If[2 < o ≤ 3, 3 - o, 0], A) → J'
  40. Vector(J, J') → u
  41. Translate(A', u) → A''
  42. Translate(B', u) → B''
  43. Translate(D'_2, u) → G
  44. Translate(I', u) → I''
  45. Polygon(A'', B'', G, I'') → q1'', a'', b'', g_2, i''
  46. Rotate(A'', If[2 < o ≤ 3, ((-(o - 2)) * π / 6), ((-π)) / 6], B'') → A'''
  47. Rotate(B'', If[2 < o ≤ 3, ((-(o - 2)) * π / 6), ((-π)) / 6], B'') → B'''
  48. Rotate(G, If[2 < o ≤ 3, ((-(o - 2)) * π / 6), ((-π)) / 6], B'') → G'
  49. Rotate(I'', If[2 < o ≤ 3, ((-(o - 2)) * π / 6), ((-π)) / 6], B'') → I'''
  50. Polygon(A''', B''', G', I''') → q1''', a''', b''', g', i'''
  51. Angle(B, A, H) → γ
  52. Angle(A, I, D) → δ
  53. Angle(J, F'_1, K) → ε
  54. Angle(I, H, F'_1) → ζ
  55. Angle(F'_1, K, D) → η
  56. Angle(D, B, A) → θ
  57. Angle(D, J, F'_1) → ι
  58. Intersect(f_1, j_1) → L
  59. Intersect(t, f_1) → M
  60. Circle(L, Distance[M, L] / 2) → c_1
  61. Angle(F'_1, E, A) → κ
  62. Intersect(c_1, f_1, 1) → N
  63. Rotate(N, ((-π)) / 6, L) → N'
  64. Ray(L, N') → n_1
  65. Circle(L, (2 * Radius[c_1])) → d_1
  66. Intersect(d_1, n_1, 1) → O
  67. Dilate(L, If[4 < o ≤ 5, 5 - o, 0], O) → L'
  68. Rotate(N, If[4 < o ≤ 5, ((-(o - 4)) * π / 6), ((-π)) / 6], L) → N'_1
  69. Segment(L, L') → p_1
  70. CircleSector(L, N'_1, N) → e_1
  71. Rotate(e_1, If[6 < o ≤ 7, ((-(o - 6)) * π / 6), ((-π)) / 6], L) → q_1
  72. Dilate(L, If[8 < o ≤ 9, 9 - o, 0], C) → L'_1
  73. Vector(L, L'_1) → v
  74. Translate(q_1, v) → r_1
  75. Rotate(r_1, If[8 < o ≤ 9, (((o - 8) * 5) * π / 6), (5 * π / 6)], L'_1) → s_1