15度角的正确画法

GeoGebra 命令及参数

1. Circle(A, B) → c
2. Point(c) → C
3. Line(A, C) → f
4. Intersect(c, f, 2) → D
5. Circle(C, D) → d
6. Circle(D, C) → e
7. Intersect(d, e, 2) → E
8. Intersect(d, e, 1) → F
9. Line(E, F) → g
10. Intersect(c, g, 1) → G
11. Intersect(c, g, 2) → H
12. Circle(C, Segment[A, C]) → h
13. Intersect(c, h, 1) → I
14. Circle(I, Radius[h]) → k
15. Intersect(c, k, 1) → J
16. Circle(J, Radius[k]) → p
17. Circle(D, Segment[J, D]) → q
18. Intersect(c, q, 1) → K
19. Circle(K, Radius[q]) → r
20. Intersect(c, h, 2) → L
21. Circle(L, Radius[r]) → s
22. Circle(I, Segment[G, I]) → t
23. Intersect(c, t, 2) → M
24. Circle(M, Radius[t]) → c_1
25. Circle(C, Segment[M, C]) → d_1
26. Intersect(c, d_1, 2) → N
27. Circle(N, Radius[d_1]) → e_1
28. Circle(H, Segment[L, H]) → f_1
29. Circle(L, Segment[N, L]) → g_1
30. Circle(K, Segment[H, K]) → h_1
31. Intersect(c, h_1, 2) → O
32. Circle(O, Radius[h_1]) → k_1
33. Circle(D, Segment[O, D]) → p_1
34. Intersect(c, p_1, 2) → P
35. Circle(P, Radius[p_1]) → q_1
36. Circle(J, Segment[P, J]) → r_1
37. Circle(G, Segment[J, G]) → s_1
38. Intersect(d_1, c_1) → Q, R, ,
39. Segment(R, Q) → i
40. Intersect(c, i) → S,
41. Ray(A, S) → j
42. Ray(A, C) → l
43. Angle(C, A, S) → α