动画50：圆与三角形的动态几何构造

GeoGebra 命令及参数

1. Circle(A, B) → c
2. Point(c) → C
3. Segment(A, C) → a
4. OrthogonalLine(C, a) → b
5. Rotate(C, °, A) → C'
6. CircleArc(A, C', C) → d
7. Point(d) → D
8. Segment(D, C) → e
9. Circle(A, (0.2 * a)) → f
10. Circle(C, (0.2 * a)) → g
11. Intersect(g, b, 2) → E
12. Intersect(g, e, 1) → F
13. Segment(A, C) → h
14. Segment(A, D) → i
15. CircleSector(C, E, F) → k
16. Dilate(A, If[0 < j ≤ 1, 1 - j, 0], C) → A'
17. Dilate(A, If[0 < j ≤ 1, 1 - j, 0], D) → A'_1
18. Segment(A, A'_1) → l
19. Segment(A, A') → m
20. Dilate(C, If[1 < j ≤ 2, 2 - j, 0], A) → C'_1
21. Vector(C, C'_1) → u
22. Translate(k, u) → k'
23. Line(A, e) → n
24. Intersect(f, i, 1) → G
25. Intersect(f, n, 1) → H
26. Angle(G, A, H) → α
27. Rotate(k', If[2 < j ≤ 3, ((-(j - 2)) * α), (-α)], A) → k''
28. Translate(E, u) → E'
29. Rotate(E', (-α), A) → E''
30. Intersect(f, m, 1) → I
31. Dilate(C, If[3 < j ≤ 4, 4 - j, 0], A) → C'_2
32. Vector(C, C'_2) → v
33. Translate(k, v) → k'_1
34. Angle(H, A, E'') → β
35. Rotate(k'_1, If[4 < j ≤ 5, ((j - 4) * β), β], A) → p
36. CircleArc(A, C, D) → q
37. Point(b) → J
38. Ray(C, J) → r