球面上的 Droz-Farny 线

GeoGebra 命令及参数

1. Sphere(A, 1) → a
2. PointIn(a) → B
3. PointIn(a) → C
4. PointIn(a) → D
5. Plane(A, B, C) → b
6. Plane(A, B, D) → c
7. Plane(A, C, D) → d
8. IntersectPath(b, a) → e
9. IntersectPath(c, a) → f
10. IntersectPath(d, a) → g
11. OrthogonalLine(A, c) → i
12. OrthogonalLine(A, b) → j
13. Plane(C, i) → k
14. IntersectPath(k, a) → q
15. Plane(D, j) → m
16. IntersectPath(m, a) → r
17. OrthogonalLine(A, d) → h
18. Plane(B, h) → l
19. IntersectPath(l, a) → p
20. Intersect(r, p, 1) → E
21. Line(A, E) → n
22. Circle(E, 1, n) → s
23. Point(s) → F
24. Rotate(F, π / 2, n) → F'
25. Plane(F, n) → o
26. Plane(F', n) → t
27. IntersectPath(o, a) → c_1
28. IntersectPath(t, a) → d_1
29. Intersect(d_1, e, 1) → G
30. Intersect(c_1, e, 2) → H
31. Intersect(g, c_1, 1) → I
32. Intersect(d_1, g, 2) → J
33. Midpoint(G, H) → K
34. Midpoint(I, J) → L
35. Line(A, K) → f_1
36. Line(L, A) → g_1
37. Intersect(f_1, e, 1) → M
38. Intersect(g_1, g, 2) → N
39. Intersect(c_1, f, 2) → O
40. Intersect(f, d_1, 2) → P
41. Midpoint(O, P) → Q
42. Line(A, Q) → h_1
43. Intersect(h_1, f, 1) → R
44. Circle(M, N, R) → e_1
45. Sequence(Tool1[A, B, C, D, Rotate[F, ((w * 2) * π / 72)]], w, 1, 72) → L_1