Bryan Johnson's Triangle Theorem

Bryan Johnson's Triangle Theorem
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2019-10-17 23:00
①本范例演示了Bryan Johnson提出的三角形定理,涉及三角形与平行四边形的动态关系;②核心数学概念包括几何作图、旋转、角度、向量与多边形构造;③作图要点提炼自GeoGebra命令:Segment(线段)、Rotate(旋转)、Angle(角度)、Ray(射线)、Point(点)、Polygon(多边形)、Circle(圆)、Intersect(交点)、Min(最小值)、CircleSector(圆扇形)、Dilate(缩放)、Vector(向量)、Translate(平移);④适合高中及以上数学学习者,用于理解几何定理的证明与可视化。

GeoGebra 命令及参数

  1. Segment(A, B) → f
  2. Rotate(B, (a * π / 180), A) → B'
  3. Angle(B, A, B') → α
  4. Ray(A, B') → g
  5. Point(g) → C
  6. Segment(B, C) → h
  7. Segment(A, C) → i
  8. Polygon(A, B, C) → poly1, c, a_1, b
  9. Rotate(A, If[0 < d ≤ 1, (d * π / 3), π / 3], A) → A'
  10. Rotate(C, If[0 < d ≤ 1, (d * π / 3), π / 3], A) → C'
  11. Rotate(B, If[0 < d ≤ 1, (d * π / 3), π / 3], C) → B'_1
  12. Rotate(C, If[0 < d ≤ 1, (d * π / 3), π / 3], C) → C'_1
  13. Segment(A, B) → q
  14. Rotate(A, If[2 < d ≤ 3, ((d - 2) * π / 3), π / 3], A) → A'_3
  15. Rotate(C, (o * π / 180), A) → C'_4
  16. Ray(A, C'_4) → t
  17. Rotate(B, (o * π / 180), C) → B'_3
  18. Rotate(B, (o * π / 180), A) → B'_4
  19. Ray(C, B'_3) → f_1
  20. Ray(A, B'_4) → g_1
  21. Point(t) → N
  22. Circle(C, (h * e_1)) → h_1
  23. Circle(A, (q * e_1)) → k_1
  24. Intersect(k_1, g_1, 1) → O
  25. Intersect(h_1, f_1) → P,
  26. Polygon(A, N, C) → t2, c_2, a_3, n_1
  27. Polygon(C, P, B) → t3, b_2, c_3, p_1
  28. Polygon(A, O, B) → t4, b_3, a_4, o_1
  29. Segment(A, N) → i_1
  30. Segment(N, C) → j_1
  31. Segment(A, O) → l_1
  32. Segment(O, B) → m_1
  33. Segment(C, P) → q_1
  34. Segment(B, P) → r_1
  35. Min(i, i_1) → e
  36. Circle(A, (0.2 * e)) → k
  37. Intersect(k, i, 1) → D
  38. Intersect(k, i_1, 1) → E
  39. CircleSector(A, D, E) → p
  40. Dilate(N, If[0 < d ≤ 1, 1 - d, 0], O) → N'
  41. Vector(N, N') → u
  42. Translate(N, u) → N'_1
  43. Translate(C, u) → C'_2
  44. Segment(N'_1, C'_2) → j
  45. Dilate(C, If[1 < d ≤ 2, 2 - d, 0], N) → C'_3
  46. Vector(C, C'_3) → v
  47. Translate(C, v) → C'_5
  48. Translate(P, v) → P'
  49. Segment(C'_5, P') → l
  50. Polygon(N, C, P, O) → q1, n, c_1, p_2, o_2