平行四边形折叠演示：翻折与对称的几何探究

GeoGebra 命令及参数

1. Polygon(A, C, D, B) → vierhoek1, a, c, d, b
2. Midpoint(B, D) → BD
3. Midpoint(A, C) → F
4. Midpoint(B, E) → G
5. CircleArc(B, DD, D) → e
6. Segment(B, E) → f
7. Polygon(B, A, C, E) → vierhoek2, b_1, a_1, c_1, e_1
8. Polygon(B, E, D) → driehoek1, d_1, b_2, e_2
9. Rotate(B, (((-(s - 1)) * 180))°, e_1) → B'
10. Rotate(E, (((-(s - 1)) * 180))°, e_1) → E'
11. Rotate(D, (((-(s - 1)) * 180))°, e_1) → D'
12. Polygon(B', E', D') → driehoek1', d', b', e'
13. Polygon(DD, E, B) → driehoek2, b_3, dd, e_3
14. Segment(G, F) → g
15. Polygon(G, F, C, E) → vierhoek3, g_1, f_1, c_2, e_4
16. Polygon(B, A, F, G) → vierhoek4, b_4, a_2, f_2, g_2
17. Rotate(G, (((-(s - 3)) * 180))°, f_2) → G'
18. Rotate(F, (((-(s - 3)) * 180))°, f_2) → F'
19. Rotate(C, (((-(s - 3)) * 180))°, f_2) → C'
20. Rotate(E, (((-(s - 3)) * 180))°, f_2) → E'_1
21. Polygon(G', F', C', E'_1) → vierhoek3', g', f', c', e'_1
22. Polygon(A, F, G, DD) → vierhoek5, a_3, f_3, g_3, dd_1
23. Segment(FE, F) → i
24. Polygon(FE, A, F) → driehoek3, f_4, fe, a_4
25. Rotate(FE, (((-(s - 5)) * 180))°, i) → FE'
26. Rotate(A, (((-(s - 5)) * 180))°, i) → A'
27. Rotate(F, (((-(s - 5)) * 180))°, i) → F'_1
28. Polygon(FE', A', F'_1) → driehoek3', f'_1, fe', a'
29. Polygon(B, FE, F, G) → vierhoek6, b_5, fe_1, f_5, g_4
30. Intersect(g_3, i) → H
31. OrthogonalLine(H, g', xOyPlane) → j
32. Line(BD, F) → n
33. Point(n) → K
34. CircleArc(K, C, A) → p
35. Polygon(G, H, F) → driehoek4, f_6, g_5, h_1
36. Intersect(f_6, Line[FE, GG]) → J
37. OrthogonalLine(H, b) → k
38. Intersect(f_5, k) → I
39. Polygon(G, H, I) → driehoek5, i_1, g_6, h_2
40. Polygon(FE, F, L) → driehoek6, l, fe_2, f_7
41. Intersect(f_6, f_7) → M
42. Segment(G, M) → m
43. Segment(H, M) → q
44. CircleArc(F, FA, A) → h