单位分数演示

单位分数演示
几何画板及绘图内容加载中,请稍等……
2017-05-23 07:35
①本范例通过动态演示展示单位分数的概念及其在几何中的应用;②涉及核心数学概念包括分数、几何图形构造、三维向量与抛物线;③构造要点:使用Random, Element, Sequence, Segment, Point, OrthogonalLine, Intersect, Polygon等命令创建几何图形与交互元素;④适合高中数学教学,用于理解分数与几何的结合应用。

GeoGebra 命令及参数

  1. Random(5, 12) → lengthoftape
  2. Random(1, 6) → chooser
  3. Element(list2, chooser) → denominator
  4. Sequence((x(A) + (i * fractionwidth), y(A) + tapeheight), i, 0, denominator) → DotsTop
  5. Sequence((x(A) + (i * fractionwidth), y(A)), i, 0, denominator) → DotsBottom
  6. Sequence(Segment[Element[DotsBottom, i], Element[DotsTop, i]], i, 1, denominator + 1) → drawverticals
  7. Segment(Element[DotsBottom, 1], Element[DotsBottom, denominator + 1]) → horizontalbottom
  8. Segment(Element[DotsTop, 1], Element[DotsTop, denominator + 1]) → horizontaltop
  9. Segment(Element[DotsBottom, 1], Element[DotsTop, 1]) → verticalleft
  10. Segment(Element[DotsBottom, denominator + 1], Element[DotsTop, denominator + 1]) → verticalright
  11. Point(horizontalbottom) → B
  12. Point(horizontalbottom) → C
  13. OrthogonalLine(C, horizontalbottom) → f
  14. Point(horizontalbottom) → D
  15. Point(horizontalbottom) → E
  16. Point(horizontalbottom) → F
  17. Point(horizontalbottom) → G
  18. Point(horizontalbottom) → H
  19. Point(horizontalbottom) → I
  20. Point(horizontalbottom) → J
  21. Point(horizontalbottom) → K
  22. OrthogonalLine(B, horizontaltop) → g
  23. OrthogonalLine(D, horizontaltop) → h
  24. OrthogonalLine(E, horizontaltop) → i
  25. OrthogonalLine(F, horizontaltop) → j
  26. OrthogonalLine(G, horizontaltop) → k
  27. OrthogonalLine(H, horizontaltop) → l
  28. OrthogonalLine(I, horizontaltop) → m
  29. OrthogonalLine(J, horizontaltop) → n
  30. OrthogonalLine(K, horizontaltop) → p
  31. Intersect(f, horizontaltop) → L
  32. Intersect(g, horizontaltop) → M
  33. Intersect(h, horizontaltop) → N
  34. Intersect(i, horizontaltop) → O
  35. Intersect(j, horizontaltop) → P
  36. Intersect(k, horizontaltop) → Q
  37. Intersect(l, horizontaltop) → R
  38. Intersect(m, horizontaltop) → S
  39. Intersect(n, horizontaltop) → T
  40. Intersect(p, horizontaltop) → U
  41. Segment(C, L) → q
  42. Segment(B, M) → r
  43. Segment(D, N) → s
  44. Segment(E, O) → t
  45. Segment(F, P) → a
  46. Segment(G, Q) → b
  47. Segment(H, R) → c
  48. Segment(I, S) → d
  49. Segment(J, T) → e
  50. Segment(K, U) → f_1
  51. Sequence(Element[DotsTop, i], i, 2, denominator) → DotsTopRevealed
  52. Polygon(Element[DotsBottom, 1], Element[DotsBottom, denominator + 1], Element[DotsTop, denominator + 1], Element[DotsTop, 1]) → poly1, g_1, h_1, i_1, j_1