两平行线间两线交点形成的三角形

GeoGebra 命令及参数

1. Line(A_1, B_1) → a
2. Line(Varydistance, a) → b
3. Mirror(Varydistance, a) → C'
4. Line(C', a) → c_3
5. Point(c_3) → D_1
6. Point(a) → B
7. Segment(D_1, B) → d
8. Point(c_3) → C
9. Point(a) → A
10. Segment(C, A) → e
11. Angle(B, D_1, C) → α
12. Angle(D_1, B, A) → β
13. Angle(D_1, C, A) → γ
14. Angle(B, A, C) → δ
15. Intersect(d, e) → O
16. Angle(C, O, D_1) → ε
17. Angle(A, O, B) → ζ
18. Polygon(D_1, O, C) → poly1, f_1, d_1, c_1
19. Polygon(O, A, B) → poly2, e_1, c_2, g
20. Mirror(A, Varydistance) → G'
21. Mirror(B, Varydistance) → E'
22. Rotate(D_1, Rotate, O) → D
23. Rotate(O, Rotate, O) → E
24. Rotate(C, Rotate, O) → F
25. Polygon(D, E, F) → poly1', c'_1, d', e_2
26. Line(A, C) → h
27. Angle(c_3, h) → η