三角形角平分线的交点 - 内心

GeoGebra 命令及参数

1. Polygon(A, B, C) → poly1, c, a, b
2. AngularBisector(A, C, B) → d
3. AngularBisector(B, A, C) → e
4. AngularBisector(A, B, C) → f
5. Intersect(e, d) → I
6. Angle(B, A, C) → α
7. Angle(A, B, C) → β
8. Angle(A, C, B) → γ
9. OrthogonalLine(I, c) → g
10. Intersect(c, g) → D
11. OrthogonalLine(I, b) → h
12. Intersect(b, h) → E
13. OrthogonalLine(I, a) → i
14. Intersect(i, a) → F
15. Segment(I, E) → j
16. Segment(I, F) → k
17. Segment(I, D) → l
18. Circle(I, E) → p
19. Angle(A, E, I) → δ
20. Angle(I, F, B) → ε
21. Angle(I, D, B) → ζ