等腰梯形的几何性质与作图

GeoGebra 命令及参数

1. Segment(A, B) → a
2. Line(D, a) → b
3. Segment(A, D) → c
4. Midpoint(a) → D_1
5. OrthogonalLine(D_1, a) → d
6. Mirror(A, d) → A'
7. Mirror(D, d) → C
8. Segment(A', C) → c'
9. Segment(D, C) → e
10. Segment(C, A) → f
11. Segment(D, B) → g
12. Angle(D, A, B) → α
13. Angle(A, B, C) → β
14. Angle(B, C, D) → γ
15. Angle(C, D, A) → δ
16. Intersect(f, g) → E
17. Angle(D, E, A) → ε
18. Angle(C, E, B) → ζ