菱形面积计算

菱形面积计算
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2019-06-02 18:31
本范例演示如何通过构造菱形的对角线来计算其面积。涉及的核心数学概念包括菱形的性质、对角线互相垂直平分以及面积公式。作图要点包括使用 GeoGebra 命令如 Segment(线段)、LineBisector(角平分线)、Point(点)、Intersect(交点)、Polygon(多边形)、Midpoint(中点)、Rotate(旋转)和 Angle(角度)等来构建菱形并计算面积。适合初中及以上学生学习几何作图和面积计算。

GeoGebra 命令及参数

  1. Segment(A, B) → AB
  2. LineBisector(AB) → b
  3. Point(b) → C
  4. Point(b) → D
  5. Segment(C, A) → c
  6. Segment(D, A) → d
  7. Segment(B, D) → e
  8. Segment(C, B) → f
  9. Intersect(b, AB) → E
  10. Polygon(C, E, A) → poly1, a_1, c_1, e_1
  11. Polygon(C, E, B) → poly2, b_1, c_2, e_2
  12. Polygon(A, E, D) → poly3, d_4, a_2, e_3
  13. Polygon(E, B, D) → poly4, d_3, e_4, b_2
  14. Midpoint(C, A) → F
  15. Midpoint(C, B) → G
  16. Midpoint(A, D) → H
  17. Midpoint(D, B) → I
  18. Rotate(A, rotateΔ, H) → A'
  19. Rotate(E, rotateΔ, H) → E'
  20. Rotate(D, rotateΔ, H) → D'
  21. Polygon(A', E', D') → poly3', d', a', e'
  22. Rotate(C, rotateΔ, F) → C'
  23. Rotate(E, rotateΔ, F) → E'_1
  24. Rotate(A, rotateΔ, F) → A'_1
  25. Polygon(C', E'_1, A'_1) → poly1', a'_1, c', e'_1
  26. Rotate(C, rotateΔ, G) → C'_1
  27. Rotate(E, rotateΔ, G) → E'_2
  28. Rotate(B, rotateΔ, G) → B'
  29. Polygon(C'_1, E'_2, B') → poly2', b', c'_1, e'_2
  30. Rotate(E, rotateΔ, I) → E'_3
  31. Rotate(B, rotateΔ, I) → B'_1
  32. Rotate(D, rotateΔ, I) → D'_1
  33. Polygon(E'_3, B'_1, D'_1) → poly4', d'_1, e'_3, b'_1
  34. Segment(D, C) → CD
  35. Midpoint(A, E) → J
  36. Midpoint(D, C) → K
  37. Angle(C, E, A) → α
  38. Midpoint(E, B) → L
  39. Segment(A, E) → a
  40. Segment(E, B) → g
  41. Segment(C, E) → i
  42. Segment(D, E) → j
  43. Polygon(D, C, A) → poly5, a_3, d_5, c_3
  44. Polygon(D, C, B) → poly6, b_3, d_6, c_4