三角形面积动画演示 by Michael Borcherds

三角形面积动画演示 by Michael Borcherds
几何画板及绘图内容加载中,请稍等……
2017-02-26 06:12
该范例通过动画展示了三角形面积的计算方法。核心数学概念包括三角形面积公式和中线定理。使用了If, Point, Polygon, Semicircle, Intersect, Angle, Rotate, Element, Segment等GeoGebra命令。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. If(animate < 1, 0, animate - 1) → animate2
  2. Point(xAxis) → A
  3. Point(xAxis) → B
  4. Polygon(A, B, C) → poly1, c, a, b
  5. Semicircle(C, B) → d
  6. Point(d, 1 - animate) → G
  7. Intersect(f, g) → F
  8. Intersect(f, b) → R
  9. Intersect(f, a) → D
  10. Angle(G, D, C) → α
  11. Rotate(F, α, R) → S
  12. Element(Sort[{H, R}], 2) → J
  13. Rotate(F, (-α), D) → Q
  14. Rotate(D, (-α), D) → D'
  15. Rotate(R, α, R) → E'
  16. Rotate(E', (-α), D') → P
  17. If(animate < 1, D, Element[Sort[{D, E}], 1]) → I
  18. Rotate(C, (-α), D') → C'_2
  19. Rotate(D, (-α), D') → D'_1
  20. Polygon(D, E', C) → poly2, j, k, l
  21. Rotate(C, (-α), D) → C'
  22. Rotate(C, α, R) → C'_1
  23. Segment(R, C) → h
  24. Polygon(D'_1, E, C'_2) → poly2', m, n, p
  25. Polygon(A, J, I, B) → poly4, q, s, t, e
  26. Segment(C, D) → i
  27. Polygon(A, H, R) → poly3, r, a_1, h_1
  28. Segment(C, F) → f_1