两次旋转的合成会产生什么?(Turn-Turn)

两次旋转的合成会产生什么?(Turn-Turn)
几何画板及绘图内容加载中,请稍等……
2023-10-31 11:17
这个范例通过“旋转×旋转”的动态作图,展示两次旋转复合后在平面中等效为某种旋转(并可用圆/角关系刻画其效果),强调旋转参数与中心位置如何共同决定最终变换。核心数学概念包括:几何变换中的旋转(Rotation)、角度关系与复合变换、向量/线段的几何构造、以及由复合旋转形成的几何对象(如对应点、镜像/中介点的构造)。作图要点:使用 Line 画基准直线,Rotate 对点进行两次旋转,并用 Angle 标注旋转角 α、β 以及由复合结果得到的角 γ、δ;借助 Polygon 构造/连接多边形状的可视结构,并用 Point、Segment 表示旋转前后对应点与关键线段(如 Center1、Center2、A、B、C 与其对应点 A'、B'、C' 等);同时结合 If 进行条件分支(例如在不同旋转状态下选择对应对象),再用 Mirror 或相关构造辅助确定可视化所需的对称/过渡几何。该构造还通过 animator/animator1/animator2 与列表 R1R2rot1List、R1R2rot2List、AnimR1R2rot1List、AnimR1R2rot2List 实现参数化动画,使复合旋转在多种角度设置下可被观察。适合高中几何拓展、竞赛几何与动态几何教学,用于帮助学生理解“旋转的复合性质”和几何直观建模。

GeoGebra 命令及参数

  1. Line(Center1, A) → a
  2. Line(Center2, B) → c
  3. Rotate(A, α / 2, Center1) → A'
  4. Angle(A, Center1, A') → γ
  5. Line(Center1, A') → b
  6. Rotate(B, β / 2, Center2) → B'
  7. Angle(B, Center2, B') → δ
  8. Line(Center2, B') → d
  9. Polygon(C, D, E, F) → preimage, c_1, d_1, e, f
  10. Rotate(C, α, Center1) → C'
  11. Rotate(D, α, Center1) → D'
  12. Rotate(E, α, Center1) → E'
  13. Rotate(F, α, Center1) → F'
  14. Rotate(preimageList, α, Center1) → R1R2rot1List
  15. Polygon(R1R2rot1List) → R1R2rot1
  16. Rotate(R1R2rot1List, β, Center2) → R1R2rot2List
  17. Polygon(R1R2rot2List) → R1R2rot2
  18. If(animator ≤ 1, animator, 0) → animator1
  19. If(animator ≥ 1, animator - 1, 0) → animator2
  20. Rotate(preimageList, (animator1 * α), Center1) → AnimR1R2rot1List
  21. Point(AnimR1R2rot1List) → G
  22. Rotate(R1R2rot1List, (animator2 * β), Center2) → AnimR1R2rot2List
  23. Segment(AnimR1R2rot2List(1), Center2) → h
  24. Segment(Center1, AnimR1R2rot1List(1)) → g
  25. Polygon(AnimR1R2rot2List) → AnimR1R2rot2
  26. Polygon(AnimR1R2rot1List) → AnimR1R2rot1
  27. Angle(preimageList(1), Center1, AnimR1R2rot1List(1)) → Angle1
  28. Angle(R1R2rot1List(1), Center2, AnimR1R2rot2List(1)) → AnimAngle2
  29. Segment(Center1, preimageList(1)) → AnimSegmentFixed
  30. Segment(Center2, R1R2rot1List(1)) → AnimSegmentR2Fixed
  31. Rotate(preimageList, β, Center2) → R2R1rot1List
  32. Polygon(R2R1rot1List) → R2R1rot1
  33. Rotate(R2R1rot1List, α, Center1) → R2R1rot2List
  34. Polygon(R2R1rot2List) → R2R1rot2
  35. Rotate(preimageList, (animator1 * β), Center2) → AnimR2R1rot1List
  36. Rotate(R2R1rot1List, (animator2 * α), Center1) → AnimR2R1rot2List
  37. Polygon(AnimR2R1rot1List) → AnimR2R1rot1
  38. Polygon(AnimR2R1rot2List) → AnimR2R1rot2
  39. Segment(Center2, preimageList(1)) → SegmentR2R1rot1Fixed
  40. Segment(Center2, AnimR2R1rot1List(1)) → SegmentR2R1rot1Moving
  41. Angle(preimageList(1), Center2, AnimR2R1rot1List(1)) → AnimR2R1angle1
  42. Segment(Center1, R2R1rot1List(1)) → SegmentR2R1rot2Fixed
  43. Segment(Center1, AnimR2R1rot2List(1)) → SegmentR2R1rot2Moving
  44. Angle(R2R1rot1List(1), Center1, AnimR2R1rot2List(1)) → AnimR2R1angle2
  45. Mirror(C, c) → C'_{1}
  46. Mirror(D, c) → D'_{1}
  47. Mirror(E, c) → E'_{1}
  48. Mirror(F, c) → F'_{1}
  49. Polygon(C'_{1}, D'_{1}, E'_{1}, F'_{1}) → preimage', c'_{1}, d'_{1}, e'_{1}, f'_{1}
  50. Mirror(R2R1rot1, a) → R2R1rot1'
  51. Mirror(C, a) → C'_{2}
  52. Mirror(D, a) → D'_{2}
  53. Mirror(E, a) → E'_{2}
  54. Mirror(F, a) → F'_{2}
  55. Polygon(C'_{2}, D'_{2}, E'_{2}, F'_{2}) → preimage'_{1}, c'_{2}, d'_{2}, e'_{2}, f'_{2}
  56. Mirror(R1R2rot1, c) → R1R2rot1'

AI 绘图提示语参考

绘制一个动态几何演示,展示两个旋转的复合效果。先画两个旋转中心,并分别用线段连接它们与两个参考点。以第一个中心旋转一个点,标出旋转角;再以第二个中心旋转另一个点,标出对应角。构造一个四边形作为原始图形,先绕第一个中心旋转整个四边形,再绕第二个中心旋转所得图形,得到复合旋转后的四边形。同时展示反向顺序(先绕第二个中心再绕第一个中心)的结果,并用动画滑块控制两个旋转角度的变化,动态显示中间步骤的图形和连接线段,以便比较两种复合顺序的差异。
以上提示语为根据原始绘图命令整理而来,仅供参考。