梯形性质演示 by KS Wong

梯形性质演示 by KS Wong
几何画板及绘图内容加载中,请稍等……
2018-04-19 09:53
①本范例演示梯形的几何性质;②涉及核心概念:梯形定义、中位线、平行线性质、角度关系;③作图要点:使用Segment, Line, Point, Polygon, Midpoint, OrthogonalLine, Intersect, Angle等命令构建梯形及辅助线,分析中位线与底边关系;④适合初中及以上学生学习几何证明与作图。

GeoGebra 命令及参数

  1. Segment(A, B) → a_2
  2. Line(C, a_2) → b_2
  3. Point(b_2) → D
  4. Polygon(A, C, D, B) → P, a_1, a, d, b
  5. Midpoint(D, B) → E
  6. Line(A, B) → e
  7. OrthogonalLine(D, e) → f
  8. Intersect(f, e) → F
  9. Midpoint(a_2) → L
  10. Segment(A, D) → c
  11. Segment(C, B) → g
  12. Angle(B, C, D) → α
  13. Angle(C, B, A) → β
  14. Angle(C, D, A) → γ
  15. Angle(B, A, D) → δ
  16. Angle(A, C, D) → ε
  17. Angle(C, D, B) → ζ
  18. Angle(D, B, A) → η
  19. Angle(B, A, C) → θ