外切圆与内切圆

GeoGebra 命令及参数

1. Line(A, B) → a
2. Line(A, C) → b
3. Rotate(A, (-α), C) → A'
4. Angle(A', C, A) → β
5. Line(C, A') → c
6. AngularBisector(c, b) → d, e
7. AngularBisector(a, c) → f, g
8. AngularBisector(a, b) → h, i
9. Intersect(a, c) → D
10. Intersect(e, g) → E
11. Intersect(d, g) → F
12. Intersect(d, f) → G
13. OrthogonalLine(E, b) → j
14. Intersect(b, j) → H
15. OrthogonalLine(G, b) → l
16. Intersect(b, l) → J
17. OrthogonalLine(F, c) → m
18. Intersect(c, m) → K
19. Circle(F, K) → p
20. Circle(E, H) → k
21. Circle(G, J) → q
22. Intersect(e, f) → I
23. OrthogonalLine(I, b) → n
24. Intersect(b, n) → L
25. Circle(I, L) → r
26. Line(D, C) → s
27. Intersect(b, s) → M
28. Intersect(a, s) → N
29. Intersect(a, b) → O
30. Polygon(M, N, O) → poly1, o, m_1, n_1