非平行线的内错角

GeoGebra 命令及参数

1. Line(A, B) → a_1
2. Line(C, D) → b_1
3. Point(a_1) → E
4. Point(b_1) → F
5. Line(E, F) → c_1
6. Point(c_1) → G
7. Point(c_1) → H
8. Segment(A, B) → r
9. Segment(C, D) → s
10. Slope(a_1) → m_1
11. Slope(b_1) → m_2
12. Point(r) → I
13. Segment(I, B) → t
14. Point(s) → J
15. Angle(F, E, B) → a
16. Angle(E, F, J) → b
17. Angle(F, E, B) → c
18. Angle(E, F, J) → d
19. Angle(D, F, E) → e
20. Angle(I, E, F) → f
21. Angle(D, F, E) → α
22. Angle(I, E, F) → β
23. Angle(B, E, G) → γ