展示同位角相等

GeoGebra 命令及参数

1. Line(A, B) → a
2. Point(a) → C
3. Line(D, a) → b
4. Line(D, C) → c
5. Midpoint(D, C) → E
6. Angle(c, b) → α
7. Angle(E, C, A) → β
8. Circle(D, E) → d
9. Intersect(d, b, 2) → F
10. Segment(D, E) → e
11. Segment(D, F) → f
12. Rotate(D, -γ, E) → D'_1
13. Rotate(F, -γ, E) → F'
14. Segment(D'_1, F') → f'
15. Rotate(D, -γ, E) → D'
16. Rotate(E, -γ, E) → E'
17. Segment(D', E') → e'
18. Angle(e', f') → δ
19. Point(a) → G
20. Segment(D, F) → u
21. Segment(C, G) → v