菱形面积演示 by Craig Mackey

GeoGebra 命令及参数

1. Line(A, B) → a
2. Point(a) → C
3. OrthogonalLine(C, a) → b
4. Point(b) → D
5. Segment(B, D) → p
6. Midpoint(p) → E
7. Mirror(D, a) → D'
8. Segment(D', B) → n
9. Midpoint(n) → J
10. Vector(J, E) → u
11. Polygon(A, D, B, D') → poly1, a_1, d, b_1, d'
12. OrthogonalLine(B, a) → c
13. OrthogonalLine(D, b) → e
14. OrthogonalLine(A, a) → f
15. OrthogonalLine(D', b) → g
16. Intersect(f, g) → F
17. Intersect(c, g) → G
18. Intersect(c, e) → H
19. Intersect(e, f) → I
20. Segment(D, D') → i
21. Segment(F, G) → j
22. Segment(G, H) → k
23. Segment(H, I) → l
24. Segment(I, F) → m
25. Segment(A, B) → h
26. Polygon(D', C, B) → poly2, b_2, d'_1, c_1
27. Midpoint(n) → R
28. Translate(R, Vector[o * u]) → R'
29. Line(J, m) → r
30. Segment(C, B) → s
31. Midpoint(s) → S
32. Vector(C, B) → v
33. Translate(C, Vector[o * (u + v)]) → C'
34. Translate(B, Vector[o * (u - v)]) → B'
35. Vector(D', B) → w
36. Translate(D', Vector[o * w]) → D''
37. Polygon(D'', C', B') → poly3, b', d'', c'
38. Vector(D', A) → z
39. Vector(A, I) → q
40. Vector(C, A) → t
41. Translate(D', Vector[o * z]) → D''_1
42. Translate(C, Vector[o * (t + q)]) → C'_1
43. Translate(A, Vector[o * (q - t)]) → A'
44. Polygon(D''_1, C'_1, A') → poly4, a', d''_1, c'_1
45. Polygon(A, B, D) → poly5, d_1, a_2, b_3
46. Polygon(D', B, C) → poly6, c_2, d'_2, b_4
47. Polygon(D', C, A) → poly7, a_3, d'_3, c_3