三角形的欧拉线

GeoGebra 命令及参数

1. Segment(C, B) → f
2. Segment(A, B) → g
3. Segment(A, C) → h
4. LineBisector(h) → cc1
5. LineBisector(f) → cc2
6. LineBisector(g) → cc3
7. Intersect(cc1, cc2) → Circumcentre
8. Intersect(cc2, f) → E_1
9. Intersect(cc1, h) → F
10. Intersect(cc3, g) → G_1
11. Segment(C, G_1) → cen1
12. Segment(B, F) → cwn2
13. Segment(A, E_1) → n
14. Intersect(cen1, cwn2) → Centroid
15. Line(A, B) → o4
16. Line(B, C) → o5
17. Line(C, A) → o6
18. OrthogonalLine(C, g) → o2
19. OrthogonalLine(A, f) → o3
20. OrthogonalLine(B, h) → o1
21. Intersect(o2, o3) → Orthocentre
22. Segment(Orthocentre, Circumcentre) → E
23. Angle(h, cc1) → cc4
24. Angle(g, cc3) → cc5
25. Angle(f, cc2) → cc6
26. Angle(h, o1) → o7
27. Angle(g, o2) → o8
28. Angle(f, o3) → o9
29. Angle(B, A, C) → η
30. Angle(C, B, A) → θ
31. Angle(A, C, B) → ι
32. Segment(Centroid, Circumcentre) → cc
33. Segment(Orthocentre, Centroid) → oc
34. Segment(Circumcentre, E_1) → d
35. Intersect(o3, f) → D
36. Segment(Orthocentre, D) → f_1
37. Intersect(n, d) → G
38. Polygon(Circumcentre, Centroid, G) → bluetri, g_1, circumcentre, centroid
39. Polygon(Centroid, A, Orthocentre) → yelltri, orthocentre, centroid_1, a_1
40. Midpoint(B, C) → H
41. Segment(H, A) → i