筝形的面积 by Math Teachers' Adventure of ICT Integration

GeoGebra 命令及参数

1. Line(A, B) → a
2. Segment(C, D) → b
3. Polygon(B, D, A, C) → Vieleck1, b_1, d, a_1, c
4. Segment(A, B) → e
5. Intersect(b, e) → E
6. Polygon(A, E, D) → Vieleck2, d_1, a_2, e_1
7. Polygon(A, E, C) → Vieleck3, c_1, a_3, e_2
8. Polygon(C, E, B) → Vieleck4, b_2, c_2, e_3
9. Polygon(E, B, D) → Vieleck5, d_2, e_4, b_3
10. Midpoint(D, A) → F
11. Midpoint(A, C) → G
12. Midpoint(C, B) → H
13. Midpoint(B, D) → I
14. Rotate(A, α, F) → A'_1
15. Rotate(E, α, F) → E'_1
16. Rotate(D, α, F) → D'_1
17. Polygon(A'_1, E'_1, D'_1) → Vieleck2', d', a', e'
18. Rotate(E, α, I) → E'_2
19. Rotate(B, α, I) → B'_1
20. Rotate(D, α, I) → D'
21. Polygon(E'_2, B'_1, D') → Vieleck5', d'_1, e'_1, b'
22. Rotate(A, α, G) → A'
23. Rotate(E, α, G) → E'_3
24. Rotate(C, α, G) → C'_1
25. Polygon(A', E'_3, C'_1) → Vieleck3', c', a'_1, e'_2
26. Rotate(C, α, H) → C'
27. Rotate(E, α, H) → E'
28. Rotate(B, α, H) → B'
29. Polygon(C', E', B') → Vieleck4', b'_1, c'_1, e'_3
30. Angle(D, E, A) → β
31. Segment(J, K) → f
32. Textfield(Text21) → Textfeld1
33. Textfield(Text23) → Textfeld2
34. Textfield(Text26) → Textfeld3
35. Textfield(Text28) → Textfeld4
36. Textfield(Text29) → Textfeld5
37. Polygon(L, M, N, O) → Vieleck6, l, m, n, o