圆内多边形的面积与周长

GeoGebra 命令及参数

1. Polygon(A, B, C, D) → poly1, a, b, c', d'
2. Segment(A, C) → c
3. Midpoint(c) → E
4. Segment(D, B) → d
5. Midpoint(d) → C_1
6. Line(C_1, E) → e
7. Line(A, e) → g
8. Line(B, e) → h
9. Line(C, e) → i
10. Line(D, g) → f
11. Point(e) → O1
12. OrthogonalLine(O1, e) → j
13. Intersect(h, j) → A_1
14. Circle(O1, A_1) → k
15. Intersect(k, e, 2) → D_1
16. Line(D_1, j) → m
17. Intersect(g, m) → A1
18. Circle(O1, A1) → p
19. Intersect(p, h, 2) → B1_1
20. Intersect(p, f, 2) → D1_1
21. If(Distance[A1, B1_1] > Distance[A1, D1_1], B1_1, D1_1) → B1
22. Segment(A1, B1) → l
23. OrthogonalLine(B1, l) → n
24. Intersect(i, n) → C1
25. OrthogonalLine(C1, n) → q
26. OrthogonalLine(A1, l) → r
27. Intersect(r, q) → D1
28. Polygon(A1, B1, C1, D1) → poly2, a_1, b_1, d_1, f_1
29. Midpoint(d') → F
30. Midpoint(b) → G
31. Line(F, G) → s
32. Point(s) → O2
33. Line(D, s) → t
34. Line(C, s) → c_1
35. Line(B, s) → e_1
36. Line(A, s) → g_1
37. OrthogonalLine(O2, s) → h_1
38. Intersect(t, h_1) → H
39. Circle(O2, H) → k_1
40. Intersect(k_1, s, 2) → I
41. Line(I, h_1) → i_1
42. Intersect(e_1, i_1) → B2
43. Circle(O2, B2) → p_1
44. Intersect(p_1, t, 2) → D2
45. Intersect(p_1, c_1, 1) → C2
46. Intersect(p_1, g_1, 1) → A2
47. Polygon(B2, D2, C2, A2) → poly3, a2, b2, c2, d2