双反射与相交线

GeoGebra 命令及参数

1. Polygon(A, B, C) → poly1, c, a, b
2. Line(D, E) → Line_1
3. Rotate(Line_1, (-α), E) → Line_2
4. Mirror(A, Line_1) → A'
5. Mirror(B, Line_1) → B'
6. Mirror(C, Line_1) → C'
7. Polygon(A', B', C') → poly1', c', a', b'
8. Mirror(A', Line_2) → A''
9. Mirror(B', Line_2) → B''
10. Mirror(C', Line_2) → C''
11. Polygon(A'', B'', C'') → poly1'', c'', a'', b''
12. Angle(Line_2, Line_1) → β
13. Angle(A'', E, A) → γ
14. Segment(E, A'') → e
15. Segment(E, A) → f