正弦定理的动态演示与几何构造

GeoGebra 命令及参数

1. Line(R, orientation) → b_1
2. Rotate(orientation, angleB°, R) → U'_1
3. Line(R, U'_1) → a_1
4. Circle(R, a) → c_1
5. Intersect(c_1, a_1) → Z_1, P
6. Circle(P, b) → d_1
7. Intersect(d_1, b_1) → V_1, Q
8. Segment(P, Q) → b_2
9. Segment(R, Q) → c
10. Segment(R, P) → a_2
11. Angle(Q, P, R) → γ
12. Angle(R, Q, P) → α
13. Angle(P, R, Q) → β
14. Midpoint(a_2) → A'
15. Midpoint(c) → C'
16. Midpoint(b_2) → B'
17. Midpoint(C', Q) → D
18. Midpoint(B', Q) → E
19. Midpoint(D, E) → F
20. If(sin(α) < 0, "-", "") → signsinA
21. Angle(orientation, R, U'_1) → α_2
22. Segment(P, Q) → e_1
23. Circle(P, R) → f_1
24. Intersect(f_1, b_1) → W_1, W'_1
25. Segment(P, W'_1) → g_1
26. Vector(Q, A') → u
27. Vector(R, B') → v
28. Vector(P, C') → w
29. Segment(V_1, P) → i
30. Segment(R, V_1) → l
31. Angle(P, V_1, R) → δ
32. Midpoint(R, A') → A
33. Midpoint(R, C') → B
34. Midpoint(A, B) → C