三角函数的几何解释

GeoGebra 命令及参数

1. Circle(Point[{0, 0}], 1) → c
2. Intersect(c, yAxis, 2) → A
3. Intersect(c, xAxis, 2) → B
4. Point({0, 0}) → C
5. CircleArc(C, B, A) → d
6. Point(d) → D
7. Segment(C, D) → f
8. OrthogonalLine(D, xAxis) → g
9. OrthogonalLine(D, yAxis) → h
10. Segment(C, A) → i
11. Ray(C, D) → j
12. OrthogonalLine(A, i) → k
13. Intersect(k, j) → E
14. Intersect(g, xAxis) → F
15. OrthogonalLine(B, xAxis) → l
16. Intersect(l, j) → G
17. Intersect(h, i) → H
18. Segment(A, E) → m
19. Segment(H, D) → n
20. Segment(F, D) → p
21. Segment(B, G) → q
22. Segment(C, G) → r
23. Segment(C, E) → s
24. Angle(B, C, D) → Θ