用GeoGebra演示三角形内角和为何不一定等于180°

GeoGebra 命令及参数

1. Sequence(CurveCartesian[x(O) + (f(t) * sin(s)), y(O) - t, z(O) + (f(t) * cos(s)), t, Min, Max], s, ((0.8 * π) * Rot / 24), ((1.5 * π) * Rot / 24), π / dx) → l1
2. Line(O, yAxis) → g
3. Point(l1) → B
4. Point(l1) → C
5. Point(l1) → D
6. Surface(x(O) + (f(t) * sin(s)), y(O) - t, z(O) + (f(t) * cos(s)), s, ((0.5 * π) * Rot / 24), ((1.5 * π) * Rot / 24), t, -2, 2) → a
7. Sphere(A, 2) → b
8. Point(l1) → E
9. Point(l1) → F
10. Point(l1) → G
11. CircumcircleArc(B, E, C) → c
12. CircumcircleArc(C, F, D) → d
13. CircumcircleArc(B, G, D) → e
14. PointIn(b) → H
15. PointIn(b) → I
16. CircleArc(A, H, I) → q
17. Polygon(N, M, L, K) → q1, n, m, l, k_1
18. PointIn(b) → J
19. CircleArc(A, H, J) → p
20. CircleArc(A, I, J) → r
21. PointIn(q1) → P
22. PointIn(q1) → Q
23. PointIn(q1) → R
24. Polygon(P, Q, R) → t1, r_1, p_1, q_1
25. Angle(Q, P, R) → α
26. Angle(P, R, Q) → β
27. Angle(R, Q, P) → γ
28. Ray(A, H) → i
29. Point(q, 0.5 / q) → S
30. Point(p, 0.5 / p) → T
31. Point(r, 0.5 / r) → U
32. Point(r, 2.5 / r) → V
33. CircleArc(H, S, T) → s
34. Point(q, 2 / q) → W
35. CircleArc(I, U, W) → t
36. Point(p, 2 / p) → Z
37. CircleArc(J, Z, V) → c_1
38. Point(c, 0.5 / c) → A_1
39. Point(c, 2.5 / c) → B_1
40. Point(d, 0.5 / d) → C_1
41. Point(d, 2 / d) → D_1
42. Point(e, 0.5 / e) → E_1
43. Point(e, 2.5 / e) → F_1
44. CircleArc(B, E_1, A_1) → d_1
45. CircleArc(C, C_1, B_1) → e_1
46. CircleArc(D, D_1, F_1) → f_1
47. Midpoint(n) → G_1
48. Centroid(t1) → H_1
49. Midpoint(H, J) → K_1
50. Midpoint(I, J) → L_1
51. Midpoint(L_1, K_1) → M_1
52. Midpoint(H, I) → N_1
53. Midpoint(N_1, M_1) → O_1
54. Midpoint(O_1, M_1) → P_1
55. Ray(A, P_1) → j
56. Intersect(j, b) → Q_1,
57. Midpoint(C, D) → R_1
58. Midpoint(B, D) → S_1
59. Midpoint(R_1, S_1) → U_1