点的旋转

点的旋转
几何画板及绘图内容加载中,请稍等……
2019-04-02 11:45
①本范例演示了点绕固定点旋转的动态过程;②涉及核心数学概念包括旋转、圆、多边形、角度、解析几何;③作图要点:使用DynamicCoordinates创建点,Rotate实现旋转,CircleArc绘制圆弧,Polygon构建多边形,If条件判断;④适合高中数学教学,用于理解旋转变换和坐标几何应用。

GeoGebra 命令及参数

  1. DynamicCoordinates(P0, round(x(P0)), round(y(P0))) → P
  2. Point(yAxis) → O
  3. Rotate(P, 360° - δ, O) → R4'
  4. Rotate(P, 270° + δ, O) → R4
  5. CircleArc(O, R4, R4') → c4
  6. Rotate(P, 180° + δ, O) → R3
  7. Rotate(P, 90° + δ, O) → R2
  8. Rotate(P, 270° - δ, O) → R3'
  9. CircleArc(O, R3, R3') → c3
  10. Rotate(P, 180° - δ, O) → R2'
  11. CircleArc(O, R2, R2') → c2
  12. Rotate(P, δ, O) → R1
  13. Rotate(P, 90° - δ, O) → R1'
  14. CircleArc(O, R1, R1') → c1
  15. Point(xAxis) → B
  16. Point({P, c1, Rotate[P, 90°, O], c2, Rotate[P, 180°, O], c3, Rotate[P, 270°, O], c4}) → P'
  17. Angle(P, O, P') → α
  18. Rotate(Q, α, O) → Q'_2
  19. Polygon(O, Q'_2, P') → t1, p', o, q'
  20. Polygon(O, Q, P) → t2, p, o_1, q
  21. Angle(P, Q, O) → β
  22. Angle(P', Q'_2, O) → γ
  23. If(P' ≟ P, false, true) → rotated
  24. Angle(P, O, P') → ε
  25. CircleArc(O, P, P') → d
  26. CircleArc(O, P', P) → e
  27. Angle(P', O, P) → ζ
  28. Rotate(Q, ε, O) → Q'