GoGeometry 行动180：等边三角形与垂直线动态几何演示

GeoGebra 命令及参数

1. Polygon(A, C, 3) → poly1, f, g, h, B
2. Midpoint(h) → M
3. Line(C, E) → i
4. OrthogonalLine(A, i) → j
5. OrthogonalLine(B, i) → k
6. Intersect(i, j) → F
7. Intersect(i, k) → D
8. Segment(A, C) → l
9. Rotate(A, If[0 < a ≤ 1, 1 - a, 0], A) → A'
10. Rotate(C, If[0 < a ≤ 1, (a * π / 3), π / 3], A) → C'
11. Segment(A, C') → m
12. Rotate(A, If[1 < a ≤ 2, ((-(a - 1)) * π / 3), ((-π)) / 3], C) → A'_1
13. Segment(C, A'_1) → n
14. Angle(B, D, E) → α
15. Angle(E, F, A) → β
16. Dilate(B, If[2 < a ≤ 3, 3 - a, 0], D) → B'
17. Segment(B, B') → p
18. Dilate(A, If[2 < a ≤ 3, 3 - a, 0], F) → A'_2
19. Segment(A, A'_2) → q
20. Dilate(A, If[4 < a ≤ 5, 5 - a, 0], M) → A'_3
21. Segment(A, A'_3) → r
22. Rotate(A, If[5 < a ≤ 6, ((a - 5) * π), π], M) → A'_4
23. Rotate(A'_3, If[5 < a ≤ 6, ((a - 5) * π), π], M) → G
24. Segment(A'_4, G) → r'
25. Dilate(M, If[6.5 < a ≤ 7.5, 7.5 - a, 0], F) → M'
26. Segment(M, M') → s
27. Rotate(M, If[7.5 < a ≤ 8.5, ((a - 7.5) * π / 3), π / 3], M) → M'_1
28. Rotate(M', If[7.5 < a ≤ 8.5, ((a - 7.5) * π / 3), π / 3], M) → M''
29. Segment(M'_1, M'') → s'
30. Rotate(M'_1, If[8.5 < a ≤ 9.5, ((a - 8.5) * π / 3), π / 3], D) → H
31. Rotate(M'', If[8.5 < a ≤ 9.5, ((a - 8.5) * π / 3), π / 3], D) → M'''
32. Segment(H, M''') → s''
33. Polygon(M, D, F) → t1, f_1, m_1, d