菱形的面积公式与几何构造演示

GeoGebra 命令及参数

1. Point(Circle[A, 4]) → B
2. Segment(A, B) → a
3. Point(Circle[B, 4]) → C
4. Segment(B, C) → b
5. Line(C, a) → c
6. Line(A, b) → d
7. Intersect(c, d) → D
8. Segment(A, D) → e
9. Midpoint(D, B) → E
10. Polygon(A, D, E) → poly1, e_1, a_1, d_1
11. Polygon(D, C, E) → poly2, e_2, d_2, c_1
12. Polygon(C, B, E) → poly3, e_3, c_2, b_1
13. Polygon(B, A, E) → poly4, e_4, b_2, a_2
14. Angle(D, E, A) → α
15. Angle(A, E, B) → β
16. Angle(B, E, C) → γ
17. Angle(C, E, D) → δ
18. Midpoint(e_4) → F
19. Midpoint(e_2) → G
20. Midpoint(e_3) → H
21. Midpoint(e_1) → I
22. Segment(F, G) → f
23. Point(f) → J
24. Vector(F, J) → u
25. Translate(B, u) → B'
26. Translate(A, u) → A'
27. Translate(E, u) → E'
28. Polygon(B', A', E') → poly4', e', b', a'
29. Rotate(B', g, J) → B''
30. Rotate(A', g, J) → A''
31. Rotate(E', g, J) → E''
32. Polygon(B'', A'', E'') → poly4'', e'', b'', a''
33. Rotate(C, g, H) → C'
34. Rotate(B, g, H) → B'_1
35. Rotate(E, g, H) → E'_1
36. Polygon(C', B'_1, E'_1) → poly3', e'_1, c', b'_1
37. Midpoint(e_2) → K
38. Rotate(D, g, K) → D'
39. Rotate(C, g, K) → C'_1
40. Rotate(E, g, K) → E'_2
41. Polygon(D', C'_1, E'_2) → poly2', e'_2, d', c'_1
42. Rotate(A, g, I) → A'_1
43. Rotate(D, g, I) → D'_1
44. Rotate(E, g, I) → E'_3
45. Polygon(A'_1, D'_1, E'_3) → poly1', e'_3, a'_1, d'_1
46. Point(Circle[L, 6.96]) → M
47. Segment(L, M) → i
48. Line(N, c') → h
49. Point(Circle[N, abs(3.96)]) → O
50. Segment(N, O) → j