Trammel三角形椭圆构造

GeoGebra 命令及参数

1. Point(xAxis) → A
2. Circle(A, 5) → c
3. Intersect(c, yAxis, 2) → B
4. Rotate(A, β, B) → A'
5. Segment(B, A) → f
6. Angle(A, B, A') → α
7. Polygon(A, B, A') → t1, a', a, b
8. Locus(A', A) → loc1
9. Intersect(xAxis, yAxis) → C
10. Mirror(A', C) → A''
11. Locus(A'', A) → loc2
12. Mirror(A, C) → A'_1
13. Mirror(B, C) → B'
14. Mirror(A', C) → A''_1
15. Polygon(A'_1, B', A''_1) → t1', a''_1, a'_1, b'
16. Circle(A'_1, a''_1) → d
17. Point(xAxis) → D
18. Point(xAxis) → E
19. Line(D, E) → g
20. Point(yAxis) → F
21. Point(yAxis) → G
22. Line(F, G) → h