风筝面积公式可视化几何推导与作图

GeoGebra 命令及参数

1. Polygon(A, B, C, D) → q1, a, b_1, c, d
2. Midpoint(A, B) → E
3. Midpoint(B, C) → F
4. Segment(E, F) → f
5. Segment(G, H) → g
6. Midpoint(C, D) → I
7. Segment(E, I) → h
8. Segment(E, G) → i
9. Segment(G, I) → j
10. Segment(E, H) → k
11. Segment(H, I) → m
12. Polygon(B, G, E) → t1, e, b_2, g_1
13. Polygon(G, C, I) → t2, i_1, g_2, c_1
14. Polygon(I, H, D) → t3, d_1, i_2, h_1
15. Polygon(H, E, A) → t4, a_1, h_2, e_1
16. Midpoint(E, G) → J
17. Midpoint(G, I) → K
18. Midpoint(I, H) → L
19. Midpoint(H, E) → M
20. Rotate(B, α, J) → B'
21. Rotate(G, α, J) → G'
22. Rotate(E, α, J) → E'
23. Polygon(B', G', E') → t1', e', b', g'
24. Rotate(G, α, K) → G'_1
25. Rotate(C, α, K) → C'
26. Rotate(I, α, K) → I'
27. Polygon(G'_1, C', I') → t2', i', g'_1, c'
28. Rotate(I, α, L) → I'_1
29. Rotate(H, α, L) → H'
30. Rotate(D, α, L) → D'
31. Polygon(I'_1, H', D') → t3', d', i'_1, h'
32. Rotate(H, α, M) → H'_1
33. Rotate(E, α, M) → E'_1
34. Rotate(A, α, M) → A'
35. Polygon(H'_1, E'_1, A') → t4', a', h'_1, e'_1