等腰梯形底角猜想

GeoGebra 命令及参数

1. Segment(A, B) → f
2. Rotate(B, α, A) → B'
3. Angle(B, A, B') → β
4. Rotate(A, (-α), B) → A'
5. Angle(A', B, A) → γ
6. Segment(A, B') → g
7. Segment(B, A') → h
8. Intersect(g, h) → C
9. Point(g) → D
10. Point(g) → E
11. Segment(D, E) → i
12. Point(i) → F
13. Line(F, f) → j
14. Intersect(j, h) → G
15. Polygon(A, B, G, F) → q1, a, b, g_1, f_1
16. Angle(A, F, G) → δ
17. Angle(F, G, B) → ε