动态圆的问题演示

动态圆的问题演示
几何画板及绘图内容加载中,请稍等……
2018-06-20 17:50
①这个范例动态演示了一个与圆相关的几何问题;②涉及的核心数学概念包括圆、交点、相似三角形和变换;③作图要点使用了Circle, PointIn, Intersect, Line, CircleArc, Point, Dilate, Segment, Angle, Vector, Translate, Polygon等GeoGebra命令;④适合高中数学教学和几何作图学习。

GeoGebra 命令及参数

  1. Circle(O, B_1) → c
  2. PointIn(a) → E
  3. Semicircle(O, E) → d
  4. Intersect(c, d, 1) → A
  5. Line(E, A) → f
  6. Semicircle(E, O) → e
  7. Intersect(c, e, 1) → E_1
  8. CircleArc(O, A, E_1) → g
  9. Point(g) → D
  10. Line(E, D) → h
  11. Line(A, O) → i
  12. Intersect(c, i, 2) → B
  13. Line(E, O) → j
  14. Intersect(c, h, 1) → C
  15. Line(B, C) → k
  16. Intersect(j, k) → F
  17. Line(B, D) → l
  18. Intersect(j, l) → G
  19. Dilate(O, If[0 < b ≤ 1, 1 - b, 0], A) → O'
  20. Dilate(E, If[0 < b ≤ 1, 1 - b, 0], A) → E'
  21. Segment(O, O') → m
  22. Segment(E, E') → n
  23. Angle(O, A, E) → α
  24. Dilate(O, If[0 < b ≤ 1, 1 - b, 0], B) → O'_1
  25. Segment(O, O'_1) → p
  26. Dilate(E, If[2 < b ≤ 3, 3 - b, 0], C) → E'_1
  27. Segment(E, E'_1) → q
  28. Dilate(C, If[3 < b ≤ 4, 4 - b, 0], D) → C'
  29. Segment(C, C') → r
  30. Dilate(E, If[4 < b ≤ 5, 5 - b, 0], F) → E'_2
  31. Segment(E, E'_2) → s
  32. Intersect(c, j) → H, I
  33. Dilate(F, If[5 < b ≤ 6, 6 - b, 0], I) → F'
  34. Segment(F, F') → t
  35. Dilate(B, If[7 < b ≤ 8, 8 - b, 0], G) → B'
  36. Segment(B, B') → f_1
  37. Dilate(G, If[8 < b ≤ 9, 9 - b, 0], D) → G'
  38. Segment(G, G') → g_1
  39. Dilate(B, If[9 < b ≤ 10, 10 - b, 0], F) → B'_1
  40. Segment(B, B'_1) → h_1
  41. Dilate(F, If[10 < b ≤ 11, 11 - b, 0], C) → F'_1
  42. Segment(F, F'_1) → i_1
  43. Dilate(G, If[11 < b ≤ 12, 12 - b, 0], A) → G'_1
  44. Vector(G, G'_1) → u
  45. Translate(B, u) → B'_2
  46. Translate(B', u) → B''
  47. Segment(B'_2, B'') → j_1
  48. Dilate(F, If[12 < b ≤ 13, 13 - b, 0], A) → F'_2
  49. Vector(F, F'_2) → v
  50. Translate(B, v) → B'_3
  51. Translate(B'_1, v) → J
  52. Segment(B'_3, J) → k_1
  53. Polygon(G, B, F, A) → q1, g_2, b_1, f_2, a_1