相交弦性质及其证明（二）

GeoGebra 命令及参数

1. Circle(A, B) → c
2. Point(c) → C
3. Point(c) → D
4. Point(c) → E
5. Point(c) → F
6. Segment(C, D) → a
7. Segment(F, E) → b
8. Intersect(a, b) → G
9. Segment(F, G) → d
10. Segment(G, E) → e
11. Segment(C, G) → f
12. Segment(G, D) → g
13. Circle(A_1, B_1) → c_1
14. Point(c_1) → C_1
15. Point(c_1) → D_1
16. Point(c_1) → E_1
17. Point(c_1) → F_1
18. Segment(C_1, D_1) → a_1
19. Segment(F_1, E_1) → b_1
20. Intersect(a_1, b_1) → G_1
21. Segment(F_1, G_1) → d_1
22. Segment(G_1, E_1) → e_1
23. Segment(C_1, G_1) → f_1
24. Segment(G_1, D_1) → g_1
25. Segment(D, E) → k
26. Segment(F, C) → l
27. Polygon(G, E, D) → poly1, d_2, g_2, e_2
28. Polygon(G, F, C) → poly2, c_2, g_3, f_2
29. Angle(D, G, F) → α
30. Rotate(G, If[0 ≤ m < 1, (-((m * α))), (-α)], G) → G'
31. Rotate(F, If[0 ≤ m < 1, (-((m * α))), (-α)], G) → F'
32. Rotate(C, If[0 ≤ m < 1, (-((m * α))), (-α)], G) → C'
33. Polygon(G', F', C') → poly2', c', g', f'
34. Mirror(G', g) → G''
35. Mirror(F', g) → F''
36. Mirror(C', g) → C''
37. Polygon(G'', F'', C'') → poly2'', c'', g'', f''
38. Line(D, C) → p
39. Dilate(G'', If[0 < o ≤ 1, ((o - 1) * q), q], G) → G'''
40. Dilate(F'', If[0 < o ≤ 1, 1 - o, 0], D) → F'''
41. Dilate(C'', If[0 < o ≤ 1, 1 - o, 0], E) → C'''
42. Polygon(G, C''', F''') → poly3, f''', g_4, c'''
43. Angle(F, G, C) → β
44. Distance(G, C''') → s
45. Distance(G, F''') → t
46. Distance(G, C''') → u
47. Distance(G, F''') → v
48. Distance(G, F) → w
49. Distance(G, C) → i_1