以Exeter点为焦点内接抛物线

GeoGebra 命令及参数

1. Line(A, B) → a
2. Line(B, C) → b
3. Line(C, A) → c
4. Circle(A, B, C) → d
5. Point(d) → F
6. Mirror(F, c) → F'_c
7. Mirror(F, a) → F'_a
8. Mirror(F, b) → F'_b
9. Line(F'_a, F'_b) → e
10. Parabola(F, e) → f
11. OrthogonalLine(F, e) → g
12. OrthogonalLine(F'_c, e) → h
13. OrthogonalLine(F'_a, e) → i
14. OrthogonalLine(F'_b, e) → j
15. Intersect(f, c, 1) → Z
16. Intersect(f, a, 1) → X
17. Intersect(b, j) → Y
18. Polygon(A, B, C) → poly1, c_1, a_1, b_1
19. Line(C, X) → k
20. Line(A, Y) → l
21. Line(B, Z) → m
22. Intersect(k, l) → P
23. Centroid(poly1) → G
24. Mirror(C, G) → C'
25. Mirror(A, G) → A'
26. Mirror(B, G) → B'
27. Conic(B', A, C', B, A') → p
28. Line(F, P) → n
29. Intersect(d, n) → D, S
30. Center(d) → E_1
31. Line(G, E_1) → q
32. Mirror(q, b) → q'
33. Mirror(q, c) → q'_1
34. Intersect(q'_1, q') → E