三角形面积动画演示

三角形面积动画演示
几何画板及绘图内容加载中,请稍等……
2017-02-26 06:29
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向量。使用了GeoGebra命令如Point, Semicircle, Polygon, Angle, Rotate等。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. Point(xAxis) → H
  2. Point(xAxis) → I
  3. Sort({H, I}) → list1
  4. Element(list1, 1) → A
  5. Element(list1, 2) → B
  6. DynamicCoordinates(K, Min[Max[x(K), x(A)], x(B)], y(K)) → L
  7. Semicircle(C, B) → d
  8. Polygon(A, B, C) → poly1, c, a, b
  9. Intersect(f, b) → E
  10. Intersect(f, a) → D
  11. Intersect(f, g) → F
  12. Point(d, 1 - animate) → G
  13. Angle(G, D, C) → α
  14. Polygon(D, F, C) → poly2, c_1, d_1, f_1
  15. Rotate(D, (-α), D) → D'
  16. Rotate(F, (-α), D) → F'
  17. Rotate(L, (-α), D) → C'
  18. Polygon(D', F', C') → poly2', c', d', f'
  19. Polygon(F, C, E) → poly3, e, f_2, c_2
  20. Rotate(F, α, E) → F'_1
  21. Rotate(L, α, E) → C'_1
  22. Rotate(E, α, E) → E'
  23. Polygon(F'_1, C'_1, E') → poly3', e', f'_1, c'_1
  24. Segment(E, C) → h
  25. Segment(C, D) → i
  26. Polygon(I, E, D, H) → poly4, i_1, e_1, d_2, h_1
  27. Vector(H - (0, 1), I - (0, 1)) → u
  28. Vector(I - (0, 1), H - (0, 1)) → v
  29. Vector(J, M) → w
  30. Vector(M, J) → j
  31. Vector(N, J) → k
  32. Vector(J, N) → l
  33. LaTeX("\frac{h}{2}") → text3
  34. LaTeX("Area = \frac{bh}{2}") → text4