正弦定律证明

GeoGebra 命令及参数

1. Segment(A, B) → a
2. Segment(B, C) → b
3. Segment(C, A) → c
4. OrthogonalLine(C, a) → d
5. Polygon(A, B, C) → poly1, c_1, a_1, b_1
6. Distance(A, C) → distanceAC
7. Distance(B, C) → distanceBC
8. Distance(A, B) → distanceAB
9. Line(A, B) → e
10. OrthogonalLine(C, e) → f
11. Point(e) → D
12. Intersect(f, e) → E
13. Segment(C, E) → g
14. Angle(D, E, C) → α
15. Distance(E, C) → distanceEC