角度加法公式的几何可视化

GeoGebra 命令及参数

1. Circle(O, 1) → c
2. Point(c) → A
3. Segment(O, A) → a
4. Point(c) → B
5. Segment(B, O) → b
6. Angle(A, O, B) → β
7. OrthogonalLine(B, a) → d
8. Intersect(d, a) → C
9. Angle(B, C, O) → γ
10. OrthogonalLine(A, xAxis) → e
11. Intersect(e, xAxis) → D
12. OrthogonalLine(C, xAxis) → f
13. Intersect(f, xAxis) → E
14. Segment(C, E) → sinαcosβ
15. Segment(A, D) → h
16. Segment(C, O) → i
17. OrthogonalLine(B, f) → j
18. Intersect(f, j) → F
19. Angle(F, C, B) → δ
20. Segment(B, C) → k
21. Segment(F, C) → cosαsinβ
22. Intersect(j, yAxis) → G
23. Segment(G, O) → sinαpβ
24. Angle(C, E, O) → ε
25. Angle(A, D, O) → ζ
26. Angle(B, F, C) → η
27. Segment(F, B) → sinαsinβ
28. Angle(D, O, A) → α
29. Segment(F, C) → p
30. CircleArc(O, M, N) → q
31. Segment(O, D) → cosα
32. Segment(E, O) → cosαcosβ
33. Segment(B, F) → g
34. Segment(G, B) → cosαpβ
35. Angle(O, G, B) → θ