角的加法：用度量演示角的和差关系

GeoGebra 命令及参数

1. Line(C, E) → a
2. Point(Circle[F, 4]) → G
3. Segment(F, G) → b
4. Rotate(G, 45*°, F) → G'
5. Angle(G, F, G') → α
6. Segment(F, G') → c
7. Point(Circle[H, 4]) → I
8. Segment(H, I) → d
9. Point(Circle[J, 4]) → K
10. Segment(J, K) → e
11. Point(Circle[L, 4]) → M
12. Segment(L, M) → f
13. Point(Circle[N, 4]) → O
14. Segment(N, O) → g
15. Point(Circle[P, 4]) → Q
16. Segment(P, Q) → h
17. Point(Circle[R, 4]) → S
18. Segment(R, S) → i
19. Point(Circle[T, 4]) → U
20. Segment(T, U) → j
21. Point(Circle[V, 4]) → W
22. Segment(V, W) → k
23. Rotate(Q, 45*°, P) → Q'
24. Angle(Q, P, Q') → β
25. Rotate(I, 90*°, H) → I'
26. Angle(I, H, I') → γ
27. Rotate(K, 135*°, J) → K'
28. Angle(K, J, K') → δ
29. Rotate(M, 180*°, L) → M'
30. Angle(M, L, M') → ε
31. Rotate(U, 30*°, T) → U'
32. Angle(U, T, U') → ζ
33. Rotate(S, 15*°, R) → S'
34. Angle(S, R, S') → η
35. Rotate(O, 60*°, N) → O'
36. Angle(O, N, O') → θ
37. Rotate(W, 75*°, V) → W'
38. Angle(W, V, W') → ι
39. Segment(P, Q') → l
40. Segment(L, M') → m
41. Segment(H, I') → n
42. Segment(J, K') → p
43. Segment(T, U') → q
44. Segment(R, S') → r
45. Segment(N, O') → s
46. Segment(V, W') → t
47. Point(Circle[Z, 4]) → A_1
48. Segment(Z, A_1) → a_1
49. Rotate(A_1, 120*°, Z) → B_1
50. Angle(A_1, Z, B_1) → κ
51. Segment(Z, B_1) → b_1
52. Point(Circle[C_1, 4]) → D_1
53. Segment(C_1, D_1) → c_1
54. Rotate(D_1, 150*°, C_1) → E_1
55. Angle(D_1, C_1, E_1) → λ
56. Segment(C_1, E_1) → d_1