用绳子画椭圆

GeoGebra 命令及参数

1. Circle(A, g) → h
2. Circle(B, e) → k
3. Intersect(h, k, 1) → C_1
4. Ellipse(A, B, C_1) → p
5. Line(A, B) → i
6. Point(p) → B'
7. Segment(A, B') → s_1
8. Segment(B, B') → s_2
9. Segment(A, B) → a_1
10. Midpoint(a_1) → G
11. OrthogonalLine(G, a_1) → b_1
12. Intersect(p, b_1) → F, E
13. Line(A, B) → c
14. Intersect(p, c) → C_2, D
15. Segment(E, F) → d
16. Segment(C_2, D) → f
17. Distance(G, D) → distanceGD
18. Distance(G, E) → distanceGE
19. Segment(G, E) → b
20. Segment(G, D) → a
21. Polygon(H, I, J, K) → q1, h_1, i_1, j, k_1
22. Textfield(s) → InputBox1