分数圆在数轴上的演示

分数圆在数轴上的演示
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2020-03-21 22:35
①本范例演示了如何在数轴上通过绘制分数对应的圆来直观理解分数大小关系;②涉及的核心数学概念包括分数表示、数轴、圆的几何性质、几何变换(旋转、镜像);③作图要点提炼自构造摘要,使用了Intersect(交点)、Circle(圆)、Line(直线)、Rotate(旋转)、Mirror(镜像)、Parabola(抛物线)、Midpoint(中点)、Center(中心)、CircleArc(圆弧)、Point(点)、OrthogonalLine(垂线)等GeoGebra命令/对象;④适合初中及以上数学学习者,用于辅助理解分数、几何变换及数轴表示。

GeoGebra 命令及参数

  1. Intersect(yAxis, f) → B
  2. Circle(B, 1 / 2) → c
  3. Intersect(c, xAxis, 1) → E
  4. Line(T, xAxis) → m
  5. Circle(T, 1 / 4) → t
  6. Rotate(m, (π * ((2 * num)) / (num + denom)), T) → xAxis'_1
  7. Intersect(t, m) → O, Q
  8. Mirror(O, xAxis'_1) → O'
  9. Intersect(t, xAxis'_1, 2) → R
  10. Intersect(eq1, xAxis) → A
  11. Intersect(g, eq1) → C
  12. Circle(C, A) → d
  13. Intersect(c, f, 1) → D
  14. Intersect(eq2, h) → F
  15. Intersect(eq2, xAxis) → G
  16. Circle(F, G) → e
  17. Intersect(r, yAxis) → L
  18. Mirror(r, xAxis) → r'
  19. Parabola(L, r') → s
  20. Intersect(s, vgl1) → M,
  21. Intersect(yAxis, f_1) → H
  22. Intersect(f_1, eq2) → I
  23. Midpoint(H, I) → J
  24. Circle(J, G, E) → k
  25. Center(k) → K
  26. Line(K, M) → i
  27. Intersect(k, i, 2) → N
  28. CircleArc(K, N, E) → p
  29. CircleArc(K, G, N) → q
  30. Mirror(N, eq3) → N'
  31. Intersect(f, eq3) → P
  32. Mirror(d, yAxis) → d'_1
  33. Mirror(e, yAxis) → e'_1
  34. Line(D, yAxis) → l
  35. Intersect(l, xAxis) → C_1
  36. Rotate(xAxis, 45°, C_1) → xAxis'
  37. Mirror(d, xAxis) → d'_2
  38. Mirror(e, xAxis) → e'_2
  39. Mirror(e'_2, yAxis) → p_1
  40. Mirror(d'_2, yAxis) → q_1
  41. Mirror(d'_1, xAxis') → r_1
  42. Mirror(q_1, xAxis') → s_1
  43. Mirror(e'_1, xAxis') → t_1
  44. Mirror(p_1, xAxis') → c_2
  45. Mirror(q_1, l) → d_2
  46. Mirror(e'_1, l) → e_2
  47. Mirror(c_2, xAxis) → f_2
  48. Mirror(t_1, xAxis) → g_2
  49. Intersect(eq4, xAxis) → G_1
  50. Midpoint(G_1, A) → I_1
  51. Circle(I_1, G_1) → q_2
  52. Mirror(q_2, yAxis) → r_2
  53. Mirror(r_2, l) → s_2
  54. Mirror(s_2, xAxis') → t_2
  55. Mirror(r_2, xAxis') → c_3
  56. Mirror(O', R) → O''
  57. Line(R, O'') → j
  58. Circle(O'', Distance[F, G]) → c_1
  59. Intersect(c_1, j, 2) → S
  60. Mirror(S, O'') → S'
  61. Circle(S, O'') → d_1
  62. Circle(S', O'') → e_1
  63. Intersect(s, m, 1) → V
  64. Intersect(s, m, 1) → W
  65. Point(m) → Z
  66. Circle(Z, O) → g_1
  67. Mirror(F, G) → F'
  68. OrthogonalLine(F', eq2) → a
  69. Parabola(F, a) → h_1