圆与切线作图示例

GeoGebra 命令及参数

1. Circle(A, B) → c
2. Segment(A, B) → f
3. PointIn(a) → C
4. Distance(C, c) → b
5. Circle(C, d) → e
6. Tangent(c, e) → g, h, i, j
7. Intersect(c, h) → D
8. Intersect(c, j) → E, N
9. Intersect(e, j) → F
10. Intersect(e, h) → G, L
11. Intersect(e, g) → H, K
12. Intersect(e, i) → I
13. Intersect(c, i) → J, M
14. Intersect(c, g) → O
15. Circle(D, 2) → p
16. Circle(E, 2) → q
17. Circle(O, 2) → r
18. Circle(K, 2) → s
19. Circle(I, 2) → t
20. Circle(F, 2) → c_1
21. Circle(G, 2) → d_1
22. Circle(J, 2) → e_1
23. Intersect(e_1, i, 1) → P
24. Intersect(e_1, i, 2) → Q
25. Intersect(p, h, 1) → R
26. Intersect(p, h, 2) → S
27. Intersect(c_1, j, 2) → T
28. Intersect(c_1, j, 1) → U
29. Intersect(d_1, h, 1) → V
30. Intersect(d_1, h, 2) → W
31. Intersect(s, g, 2) → Z
32. Intersect(s, g, 1) → A_1
33. Intersect(r, g, 2) → B_1
34. Intersect(r, g, 1) → C_1
35. Intersect(q, j, 2) → D_1
36. Intersect(q, j, 1) → E_1
37. Dilate(A, If[0 < k ≤ 1, 1 - k, 0], D) → A'
38. Dilate(A, If[0 < k ≤ 1, 1 - k, 0], M) → A'_1
39. Dilate(A, If[0 < k ≤ 1, 1 - k, 0], E) → A'_2
40. Dilate(A, If[0 < k ≤ 1, 1 - k, 0], O) → A'_3
41. Angle(A, O, C_1) → α
42. Angle(A, E, E_1) → β
43. Angle(A, J, Q) → γ
44. Angle(A, D, S) → δ
45. Angle(C, K, A_1) → ε
46. Intersect(t, i, 1) → F_1
47. Angle(C, I, F_1) → ζ
48. Angle(C, F, T) → η
49. Angle(C, G, W) → θ
50. Dilate(C, If[0 < k ≤ 1, 1 - k, 0], G) → C'
51. Dilate(C, If[0 < k ≤ 1, 1 - k, 0], F) → C'_1
52. Dilate(C, If[0 < k ≤ 1, 1 - k, 0], I) → C'_2
53. Dilate(C, If[0 < k ≤ 1, 1 - k, 0], K) → C'_3
54. Segment(A, A') → l
55. Segment(A, A'_1) → m
56. Segment(A, A'_2) → n
57. Segment(A, A'_3) → f_1
58. Segment(C, C') → g_1
59. Segment(C, C'_1) → h_1
60. Segment(C, C'_2) → i_1
61. Segment(C, C'_3) → j_1
62. Intersect(i, j) → G_1
63. Intersect(i, j) → H_1