平行四边形面积计算 by Ooi Soo Huat

GeoGebra 命令及参数

1. Line(A, yAxis) → b
2. Line(A, xAxis) → a
3. Point(a) → B
4. Distance(A, B) → AB
5. Line(B, b) → c
6. Point(c) → C
7. Line(C, a) → d
8. Point(d) → G
9. Intersect(b, d) → D
10. If(NearC ≟ true, C, G) → Pm
11. DynamicCoordinates(G, x(Pm), y(Pm)) → E
12. Line(E, c) → g
13. Intersect(a, g) → H
14. Circle(E, AB) → e
15. Intersect(e, d, 1) → F
16. Line(F, b) → h
17. Intersect(a, h) → I
18. Distance(C, E) → EC
19. Distance(E, H) → EH
20. If(E_B ≟ true, Polygon[E, B, H], Polygon[E, B, C]) → poly1
21. Polygon(I, B, C, F) → poly2, i, b_2, c_2, f
22. If(E_B ≟ true, Polygon[F, A, D], Polygon[F, A, I]) → poly3
23. Polygon(A, H, E, D) → poly4, a_1, h_1, e_1, d_1
24. Polygon(A, B, C, D) → poly5, a_2, b_1, c_1, d_2
25. Vector(C, D) → u
26. If(E_R ≟ true, Translate[poly1, Vector[(m * u)]], Translate[poly3, Vector[(m * (-u))]]) → Trans
27. Midpoint(D, A) → J
28. Line(J, a) → j
29. Circle(J, n) → k
30. Intersect(k, j, 1) → K
31. Line(K, h) → l
32. Circle(K, n) → p
33. Intersect(p, l, 2) → L
34. Intersect(p, l, 1) → M
35. Intersect(d, l) → N
36. Intersect(a, l) → O
37. Vector(M, O) → v
38. Vector(L, N) → w
39. Midpoint(A, B) → P
40. Circle(P, n) → q
41. Line(P, c) → r
42. Intersect(q, r, 1) → Q
43. Line(Q, j) → s
44. Circle(Q, n) → t
45. Intersect(t, s, 1) → R
46. Intersect(t, s, 2) → S
47. Intersect(c, s) → T
48. Intersect(b, s) → U
49. Vector(R, U) → u_1
50. Vector(S, T) → v_1
51. Intersect(j, c) → V
52. Circle(V, n) → f_1
53. Intersect(f_1, c) → W, Z
54. Segment(D, C) → k_1
55. Segment(C, B) → l_1
56. Segment(B, A) → m_1
57. Intersect(f_1, j, 2) → A_1
58. Line(A_1, r) → g_1
59. Circle(A_1, n) → p_1
60. Intersect(p_1, g_1, 2) → B_1
61. Intersect(p_1, g_1, 1) → C_1
62. Intersect(d, g_1) → D_1
63. Intersect(a, g_1) → E_1
64. Vector(B_1, D_1) → w_1
65. Vector(C_1, E_1) → i_1
66. Segment(A, D) → j_1
67. Angle(A, D, C) → α
68. Angle(C, B, A) → β