几何作图：圆心与三角形

GeoGebra 命令及参数

1. Point(xAxis) → C
2. Polygon(A, B, C) → t1, c, a, b
3. Circle(A, B, C) → d
4. Midpoint(b) → J
5. Circle(D, E) → e
6. Point(e) → K
7. Segment(D, E) → f
8. Midpoint(E, D) → O
9. OrthogonalLine(O, f) → g
10. Point(e) → M
11. Line(D, xAxis) → h
12. Point(h) → P
13. Angle(P, D, E) → β
14. Distance(O, E) → OE
15. Circle(O, 4) → k
16. Intersect(k, g, 1) → L
17. Rotate(D, α, D) → D'
18. Rotate(E, α, D) → E'
19. Segment(D', E') → f'
20. Line(A, B) → l
21. OrthogonalLine(B, l) → m
22. Point(c) → N
23. Point(a) → R
24. Polygon(B, N, Q, R) → q1, b_1, n, q, r
25. If(d ≟ e, true, false) → j
26. Circle(J, 0.2) → p
27. If(D' ∈ p ∧ 2.68 ≥ f ≥ 2.28, true, false) → o
28. Line(F, G) → s
29. Line(H, s) → t
30. Line(L, E) → f_1
31. Line(L, D) → g_1
32. Circle(E, 0.75) → c_1
33. Circle(D, 0.75) → d_1
34. Intersect(c_1, f_1, 1) → I
35. Intersect(d_1, g_1, 1) → S
36. Segment(L, I) → h_1
37. Segment(L, S) → i_1
38. Segment(I, E) → j_1
39. Segment(S, D) → k_1
40. Circle(L, 0.5) → e_1
41. Intersect(f_1, h_1) → T
42. Intersect(g_1, i_1) → U
43. Intersect(e_1, i_1) → V,
44. Intersect(e_1, h_1) → W,
45. CircleArc(L, V, W) → p_1