利用变换证明三角形相似 by Dan Dale

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. Point(xAxis) → D_1
12. Vector(D_1, E_1) → u
13. Polygon(D, E, F) → poly2, c_1, a_2, b_1
14. Translate(D, u) → A
15. Translate(E, u) → B'_1
16. Translate(F, u) → C'
17. Polygon(A, B'_1, C') → poly2', c', a', b'_1
18. Dilate(A, d_1, A) → A''
19. Dilate(B'_1, d_1, A) → B
20. Dilate(C', d_1, A) → C
21. Polygon(A'', B, C) → poly2'', c, a, f_1
22. Segment(A, C) → b
23. Segment(C, B) → l
24. Segment(B, A) → m