丹德林定理演示

GeoGebra 命令及参数

1. ConeInfinite((0, 0, 0), zAxis, 30*°) → a
2. Center(a) → O
3. IntersectPath(k, a) → q
4. Point(q) → K
5. Axes(a) → d, e, f
6. Point(Line[O, K]) → A
7. Point(q) → F
8. Point(Line[O, F]) → B
9. Plane(A, B_1, B) → b
10. IntersectPath(b, a) → c
11. Axes(c) → i, j
12. Vector(O, B) → vOB
13. Angle(Vector[A, B], Vector[A, O]) → β
14. Vector(O, A) → vOA
15. Rotate(vOA, β / 2, A, k) → vOA'
16. Angle(Vector[B, A], Vector[O, B]) → α
17. Rotate(vOB, α / 2, B, k) → vOB'
18. Ray(B, B') → g
19. Intersect(f, g) → G
20. OrthogonalLine(G, i, k) → h
21. Intersect(i, h) → H
22. Circle(G, H, k) → p
23. Sphere(G, H) → l
24. Intersect
25. Intersect(q, p, 3) → I
26. Circle(f, I) → r
27. Ray(A, A') → m
28. Intersect(f, m) → L
29. OrthogonalLine(L, i, k) → n
30. Intersect(i, n) → M
31. Circle(L, M, k) → s
32. Intersect
33. Intersect(q, s, 1) → N
34. Sphere(L, N) → o
35. Point(c) → P
36. Circle(f, N) → t
37. Line(O, P) → a_1
38. Intersect(a_1, r, 1) → Q
39. Intersect(a_1, t, 1) → R
40. Segment(M, P) → b_1
41. Segment(P, R) → c_1
42. Segment(Q, P) → d_1
43. Segment(P, H) → e_1
44. Plane(M, R, P) → u
45. IntersectPath(u, o) → f_1
46. Plane(H, P, Q) → v
47. IntersectPath(v, l) → g_1