用量角器测量角度

用量角器测量角度
几何画板及绘图内容加载中,请稍等……
2020-04-24 05:57
① 本范例演示了如何使用量角器(半圆仪)测量一个角的大小,通过可视化交互展示角度读数的过程。② 核心数学概念是角度的度量,涉及角的顶点、边以及角度数值的读取,同时隐含了角度与圆弧、扇形的关系。③ 作图要点:从构造摘要看,使用了GeoGebra的点(Point)、向量(Vector)、序列(Sequence)、旋转文本(RotateText)、文本(Text)、圆(Circle)、半圆(Semicircle)、圆扇形(CircleSector)、圆弧(CircleArc)和角度(Angle)命令,创建了量角器的半圆刻度、角度标记以及动态文本显示。④ 适合小学高年级或初中低年级学生学习几何入门,也可用于教师课堂演示,帮助学生直观理解量角器的使用方法和角度概念。

GeoGebra 命令及参数

  1. Point(xAxis) → A
  2. Point(xAxis) → B
  3. Vector(A, B) → u
  4. Vector(B, A) → v
  5. Sequence(Segment[((4 * cos(t)), (4 * sin(t))), ((4.3 * cos(t)), (4.3 * sin(t)))], t, 0°, 180°, 1°) → l1
  6. Sequence(Segment[((3.9 * cos(t)), (3.9 * sin(t))), ((4.3 * cos(t)), (4.3 * sin(t)))], t, 0°, 180°, 5°) → l2
  7. RotateText("0", 90°) → text1
  8. RotateText("10", (-(80°))) → text2
  9. RotateText("20", (-(70°))) → text3
  10. RotateText("30", (-(60°))) → text4
  11. RotateText("40", (-(50°))) → text5
  12. RotateText("50", (-(40°))) → text6
  13. RotateText("60", (-(30°))) → text7
  14. RotateText("70", (-(20°))) → text8
  15. RotateText("80", (-(10°))) → text9
  16. Text(90) → text10
  17. Circle((0, 0), 0.1) → c
  18. RotateText("100", 10°) → text11
  19. RotateText("110", 20°) → text12
  20. RotateText("120", 30°) → text13
  21. RotateText("130", 40°) → text14
  22. RotateText("170", 78°) → text20
  23. RotateText("160", 68°) → text17
  24. RotateText("150", 57°) → text16
  25. RotateText("140", 47°) → text15
  26. RotateText("180", 90°) → text18
  27. Circle((0, 0), 3.5) → d
  28. Circle((0, 0), 3.2) → e
  29. RotateText("0", 90°) → text19
  30. RotateText("10", 80°) → text21
  31. RotateText("20", 70°) → text22
  32. RotateText("30", 60°) → text23
  33. RotateText("40", 50°) → text24
  34. RotateText("50", 40°) → text25
  35. RotateText("60", 30°) → text26
  36. RotateText("70", 20°) → text27
  37. RotateText("80", 10°) → text28
  38. RotateText("100", (-(10°))) → text29
  39. RotateText("110", (-(20°))) → text30
  40. RotateText("130", (-(41°))) → text32
  41. RotateText("120", (-(31°))) → text31
  42. RotateText("140", (-(49°))) → text33
  43. RotateText("150", (-(58°))) → text34
  44. RotateText("160", (-(68°))) → text35
  45. RotateText("170", (-(78°))) → text36
  46. RotateText("180", (-(90°))) → text37
  47. Sequence(Segment[((3.75 * cos(t)), (3.75 * sin(t))), ((4.3 * cos(t)), (4.3 * sin(t)))], t, 0°, 180°, 10°) → l3
  48. Semicircle((-5, 0), (5, 0)) → f
  49. Point(f) → F
  50. Vector((0, 0), (0, 4.75)) → w
  51. Point(w) → G
  52. Vector(G, F) → a
  53. Circle(C, 3) → g
  54. Point(a) → I
  55. CircleSector(C, I, H) → h
  56. Point(g) → J
  57. CircleSector(C, J, I) → k
  58. CircleArc(K, M, L) → p
  59. Point(p) → O
  60. Vector(O, P) → b
  61. CircleArc(S, Q, R) → q
  62. Vector(R, T) → j
  63. Vector(C, B) → m
  64. Vector(C, A) → n
  65. Angle(B, C, F) → α