动画164：几何变换与多边形构造

GeoGebra 命令及参数

1. Polygon(A, C, B) → poly1, c, a, b
2. Segment(B, A) → f
3. Segment(B, C) → g
4. Midpoint(A, C) → M
5. Dilate(A, If[0 < d ≤ 1, 1 - d, 0], M) → A'
6. Segment(A, A') → h
7. Rotate(A, If[1 < d ≤ 2, ((d - 1) * π), π], M) → A'_1
8. Rotate(A', If[1 < d ≤ 2, ((-(d - 1)) * π), (-π)], M) → A''
9. Segment(A'_1, A'') → h'
10. Dilate(B, If[2 < d ≤ 3, 3 - d, 0], M) → C'
11. Segment(B, C') → i
12. Segment(B, M) → j
13. Segment(A, C) → k
14. Point(k) → D
15. Midpoint(D, A) → E
16. Segment(A, C) → l
17. Circle(E, D) → e
18. Midpoint(D, C) → F
19. Circle(F, D) → p
20. Line(B, D) → m
21. Intersect(e, m, 2) → G
22. Intersect(p, m, 2) → H
23. Segment(M, G) → n
24. Segment(M, H) → q
25. Circle(B, 1) → r
26. Circle(H, 1) → s
27. Intersect(s, m, 2) → J
28. Intersect(r, m, 1) → K
29. Ray(H, J) → t
30. Ray(B, K) → f_1
31. Dilate(B, If[4 < d ≤ 5, 5 - d, 0], D) → B'
32. Segment(B, B') → g_1
33. Angle(D, E, G) → α
34. Angle(C, F, H) → β
35. Rotate(D, If[5 < d ≤ 6, ((d - 5) * α), α], E) → D'
36. CircleArc(E, D, D') → c_1
37. Rotate(G, If[6 < d ≤ 7, ((d - 6) * ((2 * π) - α)), (2 * π) - α], E) → D'_1
38. CircleArc(E, G, D'_1) → d_1
39. Rotate(C, If[7 < d ≤ 8, ((d - 7) * β), β], F) → C'_1
40. CircleArc(F, C, C'_1) → e_1
41. Rotate(H, If[8 < d ≤ 9, ((d - 8) * ((2 * π) - β)), (2 * π) - β], F) → H'
42. CircleArc(F, H, H') → k_1
43. Angle(H, M, G) → γ
44. Dilate(M, If[9 < d ≤ 10, 10 - d, 0], H) → M'
45. Segment(M, M') → i_1
46. Dilate(M, If[10 < d ≤ 11, 11 - d, 0], G) → M'_1
47. Segment(M, M'_1) → j_1
48. Rotate(M, If[11 < d ≤ 12, ((-(d - 11)) * ((2 * π) - γ)), (-((2 * π) - γ))], M) → M'_2
49. Rotate(M', If[11 < d ≤ 12, ((-(d - 11)) * ((2 * π) - γ)), (-((2 * π) - γ))], M) → M''
50. Segment(M'_2, M'') → l_1
51. Ray(B, D) → h_1
52. Point(h_1) → I
53. Ray(D, I) → m_1