抛物线：焦点性质

GeoGebra 命令及参数

1. OrthogonalLine(A, f) → m
2. Intersect(c, f) → B,
3. Intersect(c, e) → C,
4. Intersect(c, d) → D,
5. Intersect(c, b) → E,
6. Intersect(c, a) → G,
7. Intersect(c, g) → H,
8. Intersect(c, h) → I,
9. Intersect(c, i) → J,
10. Intersect(c, j) → K,
11. Intersect(c, k) → L,
12. Intersect(c, l) → M,
13. Intersect(f, m) → N
14. Intersect(e, m) → O
15. Intersect(d, m) → P
16. Intersect(b, m) → Q
17. Intersect(a, m) → R
18. Intersect(g, m) → S
19. Intersect(h, m) → T
20. Intersect(i, m) → U
21. Intersect(j, m) → V
22. Intersect(k, m) → W
23. Intersect(l, m) → Y
24. Segment(Z, A_1) → n
25. OrthogonalLine(Z, n) → q
26. OrthogonalLine(A_1, n) → r
27. Point(q) → B_1
28. OrthogonalLine(B_1, q) → s
29. Intersect(s, r) → C_1
30. Point(s) → D_1
31. Segment(B_1, D_1) → t
32. Segment(D_1, C_1) → ee
33. Point(n) → E_1
34. OrthogonalLine(E_1, n) → b_1
35. Intersect(t, b_1) → F_1
36. Intersect(b_1, ee) → G_1
37. Segment(B_1, F_1) → cc
38. Segment(NN, N) → c_1
39. Segment(D_1, G_1) → dd
40. Segment(NNN, N) → a_1
41. Segment(B, BF) → d_1
42. Segment(OO, O) → e_1
43. Segment(P, P) → f_1
44. Segment(QQ, Q) → g_1
45. Segment(PP, P) → h_1
46. Segment(RR, R) → i_1
47. Segment(SS, S) → j_1
48. Segment(TT, T) → k_1
49. Segment(UU, U) → l_1
50. Segment(VV, V) → m_1
51. Segment(WW, W) → n_1
52. Segment(YY, Y) → p_1
53. Segment(OOO, O) → q_1
54. Segment(PPP, P) → r_1
55. Segment(QQQ, Q) → s_1
56. Segment(RRR, R) → t_1
57. Segment(SSS, S) → a_2
58. Segment(TTT, T) → b_2
59. Segment(UUU, U) → c_2
60. Segment(VVV, V) → d_2
61. Segment(WWW, W) → e_2
62. Segment(YYY, Y) → f_2
63. Segment(C, CF) → g_2
64. Segment(D, DF) → h_2
65. Segment(E, EF) → i_2
66. Segment(G, GF) → j_2
67. Segment(I, IF) → k_2
68. Segment(J, JF) → l_2
69. Segment(K, KF) → m_2
70. Segment(L, LF) → n_2
71. Segment(M, MF) → p_2