三角形的四大中心：外心、内心、垂心、重心演示

GeoGebra 命令及参数

1. Polygon(A, B, C) → poly1, c, a, b
2. LineBisector(A, B) → d
3. LineBisector(A, C) → e
4. LineBisector(a) → f
5. Intersect(d, e) → D
6. LineBisector(C, B) → g
7. AngularBisector(A, B, C) → h
8. AngularBisector(A, C, B) → i
9. AngularBisector(B, A, C) → j
10. Intersect(h, j) → E
11. OrthogonalLine(A, a) → k
12. OrthogonalLine(B, b) → l
13. OrthogonalLine(C, c) → m
14. Intersect(k, l) → F
15. Midpoint(A, C) → G
16. Midpoint(A, B) → H
17. Midpoint(C, B) → I
18. Line(A, I) → n
19. Line(B, G) → p
20. Line(C, H) → q
21. Intersect(n, p) → J