平行线比例定理探索

GeoGebra 命令及参数

1. Line(C, B_1) → a
2. Slope(a) → b
3. PointIn(d) → A
4. Segment(A, C) → i
5. Point(i) → B
6. Distance(A, B) → n
7. Circle(A, 1) → f
8. Line(A, a) → e
9. Intersect(f, e, 2) → D_1
10. Intersect(f, e, 1) → E_1
11. Ray(A, D_1) → g
12. Ray(A, E_1) → h
13. Point(g) → D
14. Ray(C, B_1) → j_1
15. Point(j_1) → F
16. Circle(C, 1) → k
17. Intersect(k, a, 1) → I
18. Line(B, a) → l
19. Segment(D, F) → m
20. Intersect(l, m) → E
21. Circle(B, 1) → p
22. Intersect(p, l, 2) → K
23. Intersect(p, i, 1) → L
24. CircleSector(B, K, L) → q
25. Dilate(B, If[0 < j ≤ 1, 1 - j, 0], A) → H'
26. Vector(B, H') → u
27. Translate(q, u) → q'
28. Rotate(q', If[1 < j ≤ 2, (((j - 1) * 180))°, 180°], A) → q''
29. Dilate(B, If[2 < j ≤ 3, 3 - j, 0], C) → H'_1
30. Vector(B, H'_1) → v
31. Translate(q, v) → q'_1
32. Segment(B, A) → r
33. Segment(B, C) → s
34. Segment(D, E) → t
35. Segment(E, F) → a_1
36. Ray(C, I) → b_1
37. Dilate(D, If[0 < o ≤ 1, 1 - o, 0], A) → F'
38. Vector(D, F') → w
39. Translate(D, w) → F'_1
40. Translate(E, w) → E'
41. Segment(F'_1, E') → t'
42. Translate(E, w) → J'_1
43. Translate(F, w) → G'_1
44. Segment(J'_1, G'_1) → c_1
45. Polygon(B, A, E') → poly1, j', h_1, c_2
46. Dilate(B, o - 1.5, A) → H'_2
47. Dilate(A, o - 1.5, A) → C'
48. Dilate(E', o - 1.5, A) → J''
49. Dilate(A, o - 0.5, A) → C'_1
50. Dilate(E', o - 0.5, A) → J''_1
51. Dilate(A, ((o - 0.5) * e_1), A) → C'_2
52. Dilate(E', ((o - 0.5) * e_1), A) → J''_2
53. Dilate(B, If[1.5 < o ≤ 2.5, 2.5 - o, 0], C) → H'_3
54. Dilate(E', If[1.5 < o ≤ 2.5, 2.5 - o, 0], G'_1) → J''_3
55. Polygon(H'_3, A, J''_3) → poly2, j''_3, h'_3, c_3
56. Dilate(E', If[1.5 < o ≤ 2.5, 2.5 - o, 0], G'_1) → E''