旋转对称图形演示

GeoGebra 命令及参数

1. Polygon(A, B, 3) → poly1, a, a_1, b, C
2. Midpoint(a) → D
3. Midpoint(a_1) → E
4. Segment(A, E) → c
5. Segment(D, C) → d
6. Intersect(c, d) → F
7. Rotate(A, α, F) → A'
8. Rotate(B, α, F) → B'
9. Rotate(C, α, F) → C'
10. Polygon(A', B', C') → poly1', c', a', b'
11. Polygon(G, H, I, J) → poly2, g, h, i, j
12. Segment(G, I) → e
13. Segment(J, H) → f
14. Intersect(e, f) → K
15. Rotate(G, α, K) → G'
16. Rotate(H, α, K) → H'
17. Rotate(I, α, K) → I'
18. Rotate(J, α, K) → J'
19. Polygon(G', H', I', J') → poly2', g', h', i', j'
20. Polygon(M, N, 5) → poly3, m_1, n, p, q, r, O, P, Q
21. Midpoint(p) → R
22. Midpoint(n) → S
23. Segment(Q, S) → s
24. Segment(M, R) → t
25. Intersect(t, s) → T
26. Rotate(M, α, T) → M'
27. Rotate(N, α, T) → N'
28. Rotate(O, α, T) → O'
29. Rotate(P, α, T) → P'
30. Rotate(Q, α, T) → Q'
31. Polygon(M', N', O', P', Q') → poly3', m', n', o', p', q'
32. Angle(B, A, C) → β
33. Angle(B', A', C') → γ
34. Angle(H, G, J) → δ
35. Angle(H', G', J') → ε
36. Segment(G', I') → b_1
37. Segment(J', H') → c_1
38. Intersect(c_1, b_1) → U
39. Angle(N', M', Q') → ζ
40. Angle(N, M, Q) → η
41. Segment(T, M') → d_1
42. Point(d_1) → V
43. Segment(V, N') → e_1
44. Segment(V, O') → f_1
45. Segment(V, P') → g_1
46. Segment(V, Q') → h_1
47. Polygon(W, Z, 4) → poly4, i_1, j_1, k_1, l_1, A_1, S'
48. Rotate(poly4, α, C_1) → poly4'