平行四边形的面积 by Diego Lieban

GeoGebra 命令及参数

1. Polygon(B, A, D, C) → poly1, b, a, d, c
2. Polygon(E, H, G, F) → poly2, e, h, g, f
3. Line(E, H) → i
4. Line(E, F) → j
5. Line(F, G) → k
6. Line(H, G) → l
7. Polygon(B, E, A) → poly3, a_1, b_1, e_1
8. Polygon(A, F, D) → poly4, d_1, a_2, f_1
9. Polygon(B, H, C) → poly5, c_1, b_2, h_1
10. Polygon(C, D, G) → poly6, g_1, c_2, d_2
11. Line(I, j) → n
12. Intersect(i, n) → J
13. Intersect(k, n) → K
14. Segment(J, K) → p
15. Circle(J, 0.25) → q
16. Intersect(q, p, 1) → L
17. Circle(K, 0.25) → r
18. Intersect(r, p) → M,
19. Line(N, i) → s
20. Intersect(j, s) → O
21. Intersect(l, s) → P
22. Segment(O, P) → t
23. Circle(O, 0.25) → k_1
24. Circle(P, 0.25) → p_1
25. Intersect(p_1, t) → Q,
26. Intersect(k_1, t) → R,