Varignon 3D 动画：重塑!

GeoGebra 命令及参数

1. Midpoint(A, B) → E
2. Midpoint(B, C) → F
3. Midpoint(C, D) → G
4. Midpoint(D, A) → H
5. Dilate(A, If[0 < a ≤ 1, 1 - a, 0], E) → A'
6. Segment(A, A') → f
7. Dilate(E, If[1 < a ≤ 2, 2 - a, 0], B) → E'
8. Segment(E, E') → g
9. Rotate(A, If[2 < a ≤ 3, ((-(a - 2)) * π), (-π)], E, Plane[A, E, F]) → A'_1
10. Segment(E, A'_1) → h
11. Dilate(B, If[3 < a ≤ 4, 4 - a, 0], F) → B'
12. Segment(B, B') → i
13. Dilate(F, If[4 < a ≤ 5, 5 - a, 0], C) → F'
14. Segment(F, F') → j
15. Rotate(B, If[5 < a ≤ 6, ((-(a - 5)) * π), (-π)], F, Plane[B, C, G]) → B'_1
16. Dilate(C, If[6 < a ≤ 7, 7 - a, 0], G) → C'
17. Segment(C, C') → l
18. Dilate(G, If[7 < a ≤ 8, 8 - a, 0], D) → G'
19. Segment(G, G') → m
20. Rotate(C, If[8 < a ≤ 9, ((-(a - 8)) * π), (-π)], G, Plane[C, D, H]) → C'_1
21. Segment(G, C'_1) → n
22. Dilate(D, If[9 < a ≤ 10, 10 - a, 0], H) → D'
23. Segment(D, D') → p
24. Dilate(H, If[10 < a ≤ 11, 11 - a, 0], A) → H'
25. Segment(H, H') → q
26. Rotate(D, If[11 < a ≤ 12, ((-(a - 11)) * π), (-π)], H, Plane[D, A, E]) → D'_1
27. Segment(H, D'_1) → r
28. Segment(F, B'_1) → k
29. Dilate(G, If[13 < a ≤ 14, 14 - a, 0], H) → G'_1
30. Segment(G, G'_1) → s
31. Dilate(H, If[14 < a ≤ 15, 15 - a, 0], E) → H'_1
32. Segment(H, H'_1) → t
33. Dilate(G, If[15 < a ≤ 16, 16 - a, 0], F) → G'_2
34. Vector(G, G'_2) → u
35. Translate(G, u) → G'_3
36. Translate(G'_1, u) → I
37. Segment(G'_3, I) → s'
38. Dilate(E, If[16 < a ≤ 17, 17 - a, 0], F) → E'_1
39. Vector(E, E'_1) → v
40. Translate(H, v) → H'_2
41. Translate(H'_1, v) → J
42. Segment(H'_2, J) → t'
43. Polygon(G, H, E, F) → q1, g_1, h_1, e, f_1