SSA 三角形:歧义情形

SSA 三角形:歧义情形
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2012-02-28 10:27
本范例演示了给定两边及其对角的三角形情况,这是三角形解的歧义情形。涉及的核心数学概念包括三角函数和三角形性质。通过使用GeoGebra命令如Circle, Intersect, Segment, Angle等,可以动态展示三角形的构造过程。适合用于高中预科或三角函数课程。

GeoGebra 命令及参数

  1. Circle(C, a04SidePendulum) → d
  2. Intersect(xAxis, yAxis) → A
  3. Segment(A, C) → b
  4. Angle(B_2, C, B_1) → β
  5. If(a04SidePendulum ≥ (b * sin(a06AngleGiven)), β, sweepdefault) → sweep
  6. Segment(C, B) → a
  7. Angle((1, 0), A, C) → α
  8. Polygon(A, C, B_2) → poly2, b_2, a_2, c_2
  9. Polygon(A, C, B_1) → poly1, b_1, a_1, c_1
  10. Corner(5) → dims
  11. If(a07labels ≤ 2, "A", If[a07labels ≤ 4, "B", "C"]) → text1a
  12. If(a06AngleGiven < 90°, If[a04SidePendulum < (a05SideGiven * sin(a06AngleGiven)), 0, (a05SideGiven * sin(a06AngleGiven)) < a04SidePendulum < a05SideGiven, 2, 1], If[a05SideGiven < a04SidePendulum, 1, 0]) → numtriangles
  13. Textfield(a06AngleGiven) → a03InputBox3
  14. Textfield(SidePendulumTemp) → a01InputBox1
  15. Textfield(SideGivenTemp) → a02InputBox2
  16. Max(RemoveUndefined[{x(A), x(B_1), x(B_2), x(C) + abs(((a05SideGiven * sin(a06AngleGiven)) * sin(sweepdefault / 2)))}]) → xmax0
  17. Min(If[Defined[B_1], {x(A), x(B_1), x(B_2), x(C)}, {x(A), x(C), x(C) - abs((a04SidePendulum * sin(sweep / 2)))}]) → xmin0
  18. Max(RemoveUndefined[{y(A), y(B_1), y(B_2), y(C), y(C) - a04SidePendulum}]) → ymax0
  19. Min(If[Defined[B_1], {y(A), y(B_1), y(B_2), y(C), y(C) - a04SidePendulum}, {y(A), y(C), y(C) - a04SidePendulum}]) → ymin0
  20. PolyLine((xmin0, ymin0), (xmax0, ymin0), (xmax0, ymax0), (xmin0, ymax0), (xmin0, ymin0)) → windowframe0
  21. If(xcenterratio ≥ 0.5, xcenter0 - ((xmax0 - xcenter0) * xcenterratio / (1 - xcenterratio)), xmin0) → xmin1
  22. If(xcenterratio ≥ 0.5, xmax0, xcenter0 + ((xcenter0 - xmin0) * (1 - xcenterratio) / xcenterratio)) → xmax1
  23. If(ycenterratio ≥ 0.5, ycenter0 - ((ymax0 - ycenter0) * ycenterratio / (1 - ycenterratio)), ymin0) → ymin1
  24. If(ycenterratio ≥ 0.5, ymax0, ycenter0 + ((ycenter0 - ymin0) * (1 - ycenterratio) / ycenterratio)) → ymax1
  25. PolyLine((xmin1, ymin1), (xmax1, ymin1), (xmax1, ymax1), (xmin1, ymax1), (xmin1, ymin1)) → windowframe1
  26. If(windowratio1 > dimsratio, ymax1, ycenter1 + (dimsratio * (xmax1 - xcenter1))) → ymax2
  27. If(windowratio1 < dimsratio, xmax1, xcenter1 + (ymax1 - ycenter1) / (dimsratio)) → xmax2
  28. PolyLine((xmin2, ymin2), (xmax2, ymin2), (xmax2, ymax2), (xmin2, ymax2), (xmin2, ymin2)) → windowframe2
  29. PolyLine((xmin3, ymin3), (xmax3, ymin3), (xmax3, ymax3), (xmin3, ymax3), (xmin3, ymin3)) → windowframe3
  30. Max(RemoveUndefined[tempL1]) → c
  31. RemoveUndefined({x(A), x(B_1), x(B_2), x(C) + abs((a04SidePendulum * sin(sweepdefault / 2)))}) → tempL2

AI 绘图提示语参考

绘制一个三角形,已知两边a和b,以及边a所对的角α。根据SSA条件,可能有0、1或2个解。首先画出边b,然后以点C为圆心,边a的长度为半径画圆,与x轴交于点A。接着画出角α,连接点A和C,形成边b。根据给定的边a和角α,可能有0、1或2个解,分别用不同的颜色标出可能的三角形。
以上提示语为根据原始绘图命令整理而来,仅供参考。