特殊角的三角函数在单位圆上的表示

GeoGebra 命令及参数

1. Intersect(xAxis, yAxis) → A
2. Point(xAxis) → B
3. Circle(A, B) → c
4. Rotate(B, θ, A) → B'
5. Segment(A, B') → b
6. Angle(B, A, B') → α
7. SurdText(d) → text2
8. SurdText(f) → text3
9. IsInteger(12 / a) → e
10. GCD(a, 12) → g
11. Dilate(B', 1.2, A) → B''
12. OrthogonalLine(B', h) → i
13. Intersect(h, i) → C
14. Segment(B', C) → j
15. Segment(C, A) → k