阿波罗尼斯圆与反点的西蒙线

GeoGebra 命令及参数

1. Line(A, B) → a
2. Line(B, C) → b
3. Line(C, A) → c
4. Circle(A, B, C) → d
5. Point(d) → P
6. OrthogonalLine(P, a) → e
7. OrthogonalLine(P, c) → f
8. OrthogonalLine(P, b) → g
9. Intersect(a, e) → P_c
10. Intersect(c, f) → P_b
11. Intersect(b, g) → P_a
12. Line(P_c, P_b) → h
13. OrthogonalLine(A, b) → j
14. OrthogonalLine(B, c) → k
15. Intersect(j, k) → H
16. Center(d) → D
17. Mirror(P, D) → P'
18. OrthogonalLine(P', b) → i
19. OrthogonalLine(P', a) → l
20. OrthogonalLine(P', c) → m
21. Intersect(l, a) → E
22. Intersect(b, i) → F
23. Intersect(c, m) → G
24. Line(E, G) → n
25. Midpoint(B, C) → I
26. Midpoint(C, A) → J
27. Midpoint(A, B) → K
28. Circle(K, J, I) → p
29. Angle(h, n) → α