McCall 圆构造演示：几何作图与切线性质探究

GeoGebra 命令及参数

1. Circle(A, B) → c
2. Point(c) → C
3. Point(c) → D
4. Point(c) → E
5. Segment(C, D) → f
6. Segment(D, B) → g
7. Segment(B, E) → h
8. Segment(E, C) → i
9. Angle(C, D, B) → α
10. Angle(B, E, C) → β
11. Angle(D, B, E) → γ
12. Angle(E, C, D) → δ
13. Circle(F, 4) → d
14. Point(d) → G
15. Segment(F, G) → j
16. Tangent(G, d) → k,
17. Angle(k, j) → ε
18. Point(k) → H
19. Segment(I, J) → l
20. Midpoint(l) → K
21. Circle(K, J) → e
22. Point(e) → L
23. Segment(K, L) → m
24. Angle(l, m) → ζ
25. Angle(m, l) → η
26. Circle(M, N) → p
27. Point(p) → O
28. Segment(O, M) → n
29. Segment(M, N) → q
30. Angle(N, M, O) → Central
31. Point(p) → P
32. Segment(P, O) → r
33. Segment(P, N) → s
34. Angle(N, P, O) → Inscribed
35. Circle(Q, R) → t
36. Point(t) → S
37. Segment(S, R) → a
38. Point(t) → T
39. Segment(Q, T) → b
40. Intersect(a, b) → U
41. Angle(T, U, S) → θ
42. Distance(S, U) → distanceSU
43. Distance(R, U) → distanceRU
44. Midpoint(R, U) →
45. Circle(V, W) → c_1
46. Point(c_1) → Z
47. Tangent(Z, c_1) → f_1,
48. Tangent(W, c_1) → g_1,
49. Intersect(f_1, g_1) → A_1
50. Distance(Z, A_1) → distanceZA1
51. Midpoint(Z, A_1) →
52. Distance(W, A_1) → distanceWA1
53. Midpoint(W, A_1) →