利用几何变换证明三角形相似（练习3）

GeoGebra 命令及参数

1. Ray(D, E) → f_2
2. Rotate(E, (a_3 * π / 180), D) → B'
3. Angle(E, D, B') → α
4. Ray(D, B') → g
5. Point(g) → F
6. Segment(F, E) → d
7. Segment(D, E) → f
8. Polygon(D, E, F) → poly1, c_2, a_1, b_2
9. Segment(D, F) → e
10. Angle(F, E, D) → β
11. Vector(D_1, E_1) → u
12. Polygon(D, E, F) → poly2, c_1, a_2, b_1
13. Translate(D, u) → A'
14. Translate(E, u) → B'_1
15. Translate(F, u) → C'
16. Polygon(A', B'_1, C') → poly2', c', a', b'_1
17. Dilate(A', d_1, A') → A''
18. Dilate(B'_1, d_1, A') → F_1
19. Dilate(C', d_1, A') → C
20. Polygon(A'', F_1, C) → poly2'', c'', a'', f_1
21. Segment(A', C) → k
22. Segment(C, F_1) → l
23. Segment(F_1, A') → m
24. Rotate(A'', (e_1 * π / 180), C) → A'''
25. Rotate(F_1, (e_1 * π / 180), C) → B
26. Rotate(C, (e_1 * π / 180), C) → C'''
27. Polygon(A''', B, C''') → poly2''', c''', a_4, f'
28. Rotate(A', (e_1 * π / 180), C) → A
29. Segment(A, B) → c
30. Segment(B, C) → a
31. Segment(C, A) → b