等比中项构造：埃拉托色尼均值法

GeoGebra 命令及参数

1. Polygon(A, E, 4) → poly1, a, b, c, d, C_1, D_1
2. Ray(A, D_1) → e
3. Ray(E, C_1) → f
4. Segment(A, C_1) → g
5. Point(e) → M'
6. Line(M', g) → h
7. Point(e) → N'
8. Line(N', g) → i
9. Intersect(h, f) → G
10. Intersect(i, f) → H
11. Segment(M', G) → j
12. Segment(N', H) → k
13. OrthogonalLine(M', e) → l
14. OrthogonalLine(N', e) → m
15. OrthogonalLine(G, f) → q
16. OrthogonalLine(H, f) → r
17. Intersect(q, e) → N
18. Intersect(r, e) → Q
19. Segment(G, N) → s
20. Segment(H, Q) → t
21. Point(t) → D
22. Segment(A, D) → n
23. Intersect(j, n) → B
24. Intersect(c, n) → M_1
25. Intersect(k, n) → C
26. Intersect(s, n) → O
27. Distance(B, M_1) → d_1
28. Distance(C, O) → d_2
29. Segment(D, H) → p
30. Segment(G, C) → a_1
31. Segment(C_1, B) → b_1
32. Intersect(c, f) → F
33. Intersect(d, e) → I
34. Intersect(c, d) → M