立方体、三角形与高

立方体、三角形与高
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2017-07-26 01:11
①本范例演示了立方体内部一个三角形及其高的几何关系;②涉及的核心数学概念包括立体几何、三角形几何、高线计算;③作图要点——从下方『构造摘要』提炼用到了Segment(线段)、Line(直线)、Intersect(交点)、OrthogonalLine(垂线)、Angle(角度)等GeoGebra命令/对象;④适合高中及以上学生学习和理解空间几何与平面几何的关联。

GeoGebra 命令及参数

  1. Segment(A, C) → g
  2. Line(B, g) → j
  3. Segment(A, B) → f
  4. Line(C, f) → i
  5. Intersect(i, j) → E
  6. Segment(C, E) → l
  7. Line(D, l) → n_2
  8. Segment(C, D) → h
  9. Line(B, h) → q
  10. Line(E, h) → m
  11. Intersect(m, n_2) → F
  12. Line(F, g) → c
  13. Intersect(q, c) → H
  14. Segment(A, A + (t1 * (D - A))) → g_1
  15. OrthogonalLine(C, g_1) → j_1
  16. Segment(D, D + (t1 * (H - D))) → i_1
  17. OrthogonalLine(F, i_1) → k_1
  18. Intersect(j_1, k_1) → K
  19. Segment(B, E) → k
  20. Line(A, h) → p
  21. Line(D, g) → r
  22. Intersect(r, p) → G
  23. Segment(A, G) → s
  24. Segment(D, G) → t
  25. Segment(E, F) → a
  26. Segment(F, D) → b
  27. Segment(G, H) → d
  28. Segment(F, H) → e
  29. Segment(H, B) → f_1
  30. Segment(H, H + (t1 * (A - H))) → h_1
  31. Segment(B, B + (t3 * (K - B))) → m_1
  32. Segment(F, F + (t3 * (K - F))) → n_1
  33. Segment(C, C + (t3 * (K - C))) → l_1
  34. Intersect(j_1, g_1) → I
  35. OrthogonalLine(F, i_1) → s_1
  36. Intersect(s_1, i_1) → J
  37. OrthogonalLine(B, h_1) → t_1
  38. Intersect(t_1, h_1) → O
  39. Angle(D, I, C) → α
  40. Angle(H, J, F) → γ
  41. Angle(A, O, B) → β
  42. Segment(C, C + (t2 * (I - C))) → p_1
  43. Segment(F, F + (t2 * (J - F))) → q_1
  44. Segment(B, B + (t2 * (O - B))) → r_1