两椭圆上的Poncelet五边形

GeoGebra 命令及参数

1. Conic(A, B, C, D, E) → c
2. Tangent(F, c) → a, b
3. Point(b) → G
4. Tangent(G, c) → d, e
5. Point(e) → I
6. Tangent(I, c) → f, g
7. Point(g) → J
8. Tangent(J, c) → h, i
9. Intersect(i, a) → K
10. Conic(G, I, J, K, F) → k
11. Ray(O, O + (cos(α), sin(α))) → j
12. Intersect(k, j) → H, R
13. Tangent(H, c) → l, m
14. Intersect(k, l, 2) → L
15. Intersect(k, m, 2) → M
16. Tangent(M, c) → n, p
17. Intersect(k, p, 2) → N
18. Tangent(N, c) → q, r
19. Intersect(k, r) → P, Q
20. Segment(Q, L) → s
21. Segment(L, H) → t
22. Segment(H, M) → a_1
23. Segment(M, P) → b_1
24. Segment(P, Q) → c_1