弦四边形中的欧拉直线（Euler-Geraden）作图演示

GeoGebra 命令及参数

1. Circle(A, B, C) → c
2. Point(c) → D
3. Center(c) → E
4. Line(A, B) → f
5. Line(B, C) → g
6. Line(C, D) → h
7. Line(D, A) → i
8. Line(D, B) → j
9. Line(A, C) → k
10. Intersect(j, k) → F
11. Polygon(A, B, F) → d1, f_1, a, b
12. Polygon(F, B, C) → d2, c_1, f_2, b_1
13. Polygon(F, C, D) → d3, d, f_3, c_2
14. Polygon(A, F, D) → d4, d_1, a_1, f_4
15. Centroid(d1) → G
16. Circle(A, B, F) → e
17. Center(e) → H
18. Line(G, H) → l
19. Centroid(d2) → I
20. Circle(F, B, C) → p
21. Center(p) → J
22. Line(I, J) → m
23. Centroid(d3) → K
24. Circle(D, F, C) → q
25. Center(q) → L
26. Line(L, K) → n
27. Centroid(d4) → M
28. Circle(D, A, F) → r
29. Center(r) → N
30. Line(N, M) → s
31. Intersect(m, l) → O