Billar：几何作图与变换的探索

GeoGebra 命令及参数

1. OrthogonalLine(E_2, xAxis) → b
2. OrthogonalLine(E_3, b) → e_1
3. Line(D, e_1) → e
4. Mirror(B, e_1) → N
5. OrthogonalLine(B, m) → q
6. Point(q) → E_4
7. Ray(B, E_4) → g
8. Intersect(g, e) → F
9. Intersect(e_1, g) → L
10. UnitVector(Vector[N, L]) → v_2
11. OrthogonalLine(L, e_1) → k
12. Mirror(F, k) → F'
13. UnitVector(Vector[B, L]) → v_1
14. If(y(P_0) > y(E_3), 1, 0) → test_1
15. If(y(P_0) < (2 * y(E_3)) - y(F'), 0, 1) → test_f
16. Intersect(e_1, yAxis) → E
17. Mirror(F', e_1) → F''
18. Mirror(B, k) → B'
19. Mirror(B', e_1) → C
20. Circle(B, d) → c
21. Intersect(c, q, 2) → A
22. Ray(B, A) → a
23. UnitOrthogonalVector(v) → w
24. Mirror(pic1, e_1) → pic7
25. Ray(A, B) → f
26. Angle(B, L, E_3) → β
27. Mirror(D, e_1) → D'
28. Segment(P_1, L) → h
29. Ray(L, E_4) → g_1
30. Angle(E, L, F') → γ