内接椭圆与焦点、中心的关系

GeoGebra 命令及参数

1. Line(A, B) → a
2. Line(B, C) → b
3. Line(C, A) → c
4. Centroid(Polygon[A, B, C]) → G
5. Midpoint(A, C) → D
6. Midpoint(C, B) → E
7. Midpoint(B, A) → F
8. Polygon(A, B, C) → poly1, c_1, a_1, b_1
9. Segment(B, D) → m
10. Segment(A, E) → n
11. Segment(F, C) → p
12. OrthogonalLine(A, a_1) → d
13. OrthogonalLine(B, b_1) → e
14. OrthogonalLine(C, c_1) → f
15. Intersect(d, e) → H
16. Circle(A, B, C) → g
17. Center(g) → O
18. Midpoint(H, O) → N
19. Line(B, O) → h
20. Line(A, O) → i
21. Line(C, O) → j
22. Intersect(c, h) → I
23. Intersect(b, i) → J
24. Intersect(a, j) → K
25. Mirror(K, F) → K'
26. Mirror(I, D) → I'
27. Mirror(J, E) → J'
28. Mirror(I', N) → I''
29. Mirror(J', N) → J''
30. Mirror(K', N) → K''
31. Conic(J'', I', K'', J', I'') → k
32. Point(g) → L
33. Segment(H, L) → l
34. LineBisector(l) → q