SAS几何作图练习1

SAS几何作图练习1
几何画板及绘图内容加载中,请稍等……
2015-12-08 22:22
①本范例演示了使用SAS(边角边)判定三角形全等的几何作图过程;②涉及的核心数学概念包括全等三角形判定、角度测量、线段复制与变换;③作图要点——从下方『构造摘要』提炼用到了Segment(线段)、Angle(角度)、Line(直线)、Polygon(多边形)、Mirror(镜像)、Rotate(旋转)等GeoGebra命令及对象A, B, c, C, b, α, a, D_1, E_1等;④适合初中数学几何单元教学或学生自主探究三角形全等性质。

GeoGebra 命令及参数

  1. Segment(A, B) → c
  2. Segment(A, C) → b
  3. Angle(B, A, C) → α
  4. Segment(C, B) → a
  5. Line(D_1, E_1) → d_1
  6. Polygon(A, B, C) → poly1, c_1, a_1, b_1
  7. Mirror(A, d_1) → A'
  8. Mirror(B, d_1) → B'
  9. Mirror(C, d_1) → C'
  10. Polygon(A', B', C') → poly1', c', a', b'
  11. Mirror(A, d_1) → A'_1
  12. Mirror(C, d_1) → F_2
  13. Segment(A'_1, F_2) → e_1
  14. Mirror(A, d_1) → D_2
  15. Mirror(B, d_1) → B'_1
  16. Segment(D_2, B'_1) → f_1
  17. Mirror(C, d_1) → C'_2
  18. Mirror(B, d_1) → E_2
  19. Segment(C'_2, E_2) → d_2
  20. Angle(F_2, D_2, E_2) → β
  21. Rotate(A', 72.13°, F_1) → A''
  22. Rotate(B', 72.13°, F_1) → B''
  23. Rotate(C', 72.13°, F_1) → C''
  24. Polygon(A'', B'', C'') → poly1'', c'', a'', b''
  25. Rotate(A', 72.13°, F_1) → A''_1
  26. Rotate(B', 72.13°, F_1) → B''_1
  27. Rotate(C', 72.13°, F_1) → C''_1
  28. Polygon(A''_1, B''_1, C''_1) → poly1''_1, c''_1, a''_1, b''_1
  29. Rotate(D_2, 72.13°, F_1) → D'
  30. Rotate(B'_1, 72.13°, F_1) → E
  31. Segment(D', E) → f
  32. Rotate(A'_1, 72.13°, F_1) → D
  33. Rotate(F_2, 72.13°, F_1) → F'
  34. Segment(D, F') → e
  35. Rotate(C'_2, 72.13°, F_1) → F
  36. Rotate(E_2, 72.13°, F_1) → E'
  37. Segment(F, E') → d
  38. Angle(F, D, E) → γ