平行四边形与点对称的几何作图

GeoGebra 命令及参数

1. Segment(D, A) → f
2. Segment(A, B) → g
3. Segment(B, C) → h
4. Segment(C, D) → i
5. Rotate(C, α, E) → C'
6. Rotate(D, α, E) → D'
7. Segment(C', D') → i'
8. Rotate(D, α, E) → D'_1
9. Rotate(A, α, E) → A'
10. Segment(D'_1, A') → f'
11. Rotate(A, α, E) → A'_1
12. Rotate(B, α, E) → B'
13. Segment(A'_1, B') → g'
14. Rotate(B, α, E) → B'_1
15. Rotate(C, α, E) → C'_1
16. Segment(B'_1, C'_1) → h'