伐里农定理演示

伐里农定理演示
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2015-01-10 12:27
①本范例演示了伐里农定理,即平行四边形对角线将其分为四个面积相等的三角形;②涉及核心数学概念包括平行四边形、中点、向量、面积计算;③作图要点:使用 GeoGebra 命令如 Midpoint(中点)、Translate(平移)、Polygon(多边形)、Rotate(旋转)、Segment(线段)等构建图形;④适合高中数学教学,用于理解几何定理的证明与面积关系。

GeoGebra 命令及参数

  1. Midpoint(A, B) → E
  2. Midpoint(B, C) → F
  3. Midpoint(C, D) → G
  4. Midpoint(A, D) → H
  5. Semicircle(E - F, (0, 0)) → e
  6. Semicircle((0, 0), E - F) → c
  7. Translate(Rotate[Polygon[Rotate[C, (((-180))° * Min[1, Max[0, t - 17.5]]), G], Rotate[F, (((-180))° * Min[1, Max[0, t - 17.5]]), G], Rotate[G, (((-180))° * Min[1, Max[0, t - 17.5]]), G]], (((-180))° * Min[1, Max[0, t - 18.5]]), H], ((F - E) * Min[1, Max[0, (0.5 * (t - 19.5))]])) → poly3
  8. Translate(Rotate[Rotate[Polygon[Rotate[B, (((-180))° * Min[1, Max[0, t - 16.5]]), F], Rotate[E, (((-180))° * Min[1, Max[0, t - 16.5]]), F], Rotate[F, (((-180))° * Min[1, Max[0, t - 16.5]]), F]], (((-180))° * Min[1, Max[0, t - 17.5]]), G], (((-180))° * Min[1, Max[0, t - 18.5]]), H], ((F - E) * Min[1, Max[0, (0.5 * (t - 19.5))]])) → poly2
  9. Polygon(Translate[A, ((F - E) * Min[1, Max[0, (0.5 * (t - 19.5))]])], Translate[E, ((F - E) * Min[1, Max[0, (0.5 * (t - 19.5))]])], Translate[H, ((F - E) * Min[1, Max[0, (0.5 * (t - 19.5))]])]) → poly1, a, h, j
  10. Rotate(D, (((-180))° * Min[1, Max[0, t - 6]]), H) → D'
  11. Rotate(G, (((-180))° * Min[1, Max[0, t - 6]]), H) → G'
  12. Rotate(H, (((-180))° * Min[1, Max[0, t - 6]]), H) → H'
  13. Translate(Polygon[Rotate[D, (((-180))° * Min[1, Max[0, t - 18.5]]), H], Rotate[G, (((-180))° * Min[1, Max[0, t - 18.5]]), H], Rotate[H, (((-180))° * Min[1, Max[0, t - 18.5]]), H]], ((F - E) * Min[1, Max[0, (0.5 * (t - 19.5))]])) → poly4
  14. Polygon(A, B, C, D) → poly0, a_1, b, c_1, d
  15. Segment(Vertex[poly1, 1], Vertex[poly1, 2]) → a1
  16. Segment(Vertex[poly2, 1], Vertex[poly2, 2]) → a2
  17. Segment(Vertex[poly2, 3], Vertex[poly2, 2]) → e2
  18. Segment(Vertex[poly2, 3], Vertex[poly2, 1]) → b1
  19. Segment(Vertex[poly3, 3], Vertex[poly3, 2]) → e3
  20. Segment(Vertex[poly1, 1], Vertex[poly1, 3]) → d2
  21. Segment(Vertex[poly1, 2], Vertex[poly1, 3]) → e1
  22. Segment(Vertex[poly4, 2], Vertex[poly4, 3]) → e4
  23. Segment(Vertex[poly4, 1], Vertex[poly4, 3]) → d1
  24. Segment(Vertex[poly4, 1], Vertex[poly4, 2]) → c2
  25. Segment(E, Point[Segment[E, F], Min[1, Max[0, (3 * (t - 4 / 3))]]]) → f1
  26. Segment(A, Point[Segment[A, C], Min[1, Max[0, (3 * (t - 17 / 6))]]]) → f2
  27. Segment(E, F) → f11
  28. Segment(A, C) → f22
  29. Segment(H, Point[Segment[H, G], Min[1, Max[0, (3 * (t - 29 / 6))]]]) → f3
  30. Segment(H, G) → f33
  31. Polygon(A, B, C, D) → poly5, a_2, b_1, c_2, d_1
  32. Segment(E, Point[Segment[E, H], (3 * (t - 28 / 3))]) → g1
  33. Segment(B, Point[Segment[B, D], (3 * (t - 65 / 6))]) → g2
  34. Segment(Vertex[poly3, 2], Vertex[poly3, 1]) → b2
  35. Segment(Vertex[poly3, 1], Vertex[poly3, 3]) → c1
  36. If(2 > t > 1, Point[poly2, t - 1], If[4 ≥ t ≥ 2.5, Point[Polygon[B, A, C], t - 2.5], If[5.5 ≥ t ≥ 4.5, Point[Polygon[D, H, G], t - 4.5], If[7.5 ≥ t ≥ 6, Point[Polygon[D, A, C], t - 6], If[10 > t > 9, Point[poly1, t - 9], If[12 ≥ t ≥ 10.5, Point[Polygon[A, B, D], t - 10.5], If[13 > t > 12, Point[poly3, t - 12], If[t > 13.5, Point[Polygon[C, B, D], t - 13.5]]]]]]]]) → I
  37. Segment(E, H) → g11
  38. Segment(B, D) → g22
  39. Segment(F, Point[Segment[F, G], (3 * (t - 37 / 3))]) → g3
  40. Segment(F, G) → g33
  41. Corner(1, 5) → J

AI 绘图提示语参考

画一个平行四边形,标出其对角线,并证明对角线将平行四边形分成四个面积相等的三角形。首先绘制平行四边形,然后找到四条边的中点,连接这些中点形成一个小平行四边形。接着,用半圆连接小平行四边形的对边,展示面积分割关系。
以上提示语为根据原始绘图命令整理而来,仅供参考。