风筝形面积演示

GeoGebra 命令及参数

1. Polygon(B, A, D, C) → q1, b_1, a, d, c
2. Midpoint(B, A) → E
3. Midpoint(C, D) → F
4. Point(a) → G
5. Point(c) → H
6. Segment(H, E) → f
7. Segment(E, G) → g
8. Segment(G, F) → h
9. Segment(F, H) → i
10. Segment(E, F) → j
11. Segment(H, G) → k
12. Intersect(k, j) → I
13. Midpoint(E, H) → J
14. Midpoint(H, F) → K
15. Midpoint(F, G) → L
16. Midpoint(G, E) → M
17. Polygon(B, E, H) → t1, h_1, b_2, e
18. Polygon(H, F, C) → t2, c_1, h_2, f_1
19. Polygon(E, A, G) → t3, g_1, e_1, a_1
20. Polygon(G, F, D) → t4, d_1, g_2, f_2
21. Rotate(B, α, J) → B'
22. Rotate(E, α, J) → E'
23. Rotate(H, α, J) → H'
24. Polygon(B', E', H') → t1', h', b', e'
25. Rotate(H, α, K) → H'_1
26. Rotate(F, α, K) → F'
27. Rotate(C, α, K) → C'
28. Polygon(H'_1, F', C') → t2', c', h'_1, f'
29. Rotate(G, α, L) → G'
30. Rotate(F, α, L) → F'_1
31. Rotate(D, α, L) → D'
32. Polygon(G', F'_1, D') → t4', d', g', f'_1
33. Rotate(E, α, M) → E'_1
34. Rotate(A, α, M) → A'
35. Rotate(G, α, M) → G'_1
36. Polygon(E'_1, A', G'_1) → t3', g'_1, e'_1, a'
37. Rotate(H, 90°, I) → H'_2
38. Angle(H, I, H'_2) → β