三角形面积演示 by mathspace

GeoGebra 命令及参数

1. Point({7, 2}) → I
2. Point({2, 2}) → G
3. Segment(I, G) → k
4. Point({-3, 2}) → F
5. Segment(F, G) → j
6. Point(b_{2}) → C
7. Intersect(b_{2}, a) → D
8. Point(j) → A
9. Vector(D, A) → u
10. Point(k) → B
11. Polygon(C, D, B) → poly1, b_1, c, d
12. Polygon(C, D, A) → poly2, a_1, c_1, d_1
13. Midpoint(d_1) → E
14. Midpoint(d) → H
15. Rotate(C, (-α), H) → C'_2
16. Rotate(D, (-α), H) → D'_1
17. Rotate(B, (-α), H) → B'_1
18. Polygon(C'_2, D'_1, B'_1) → poly1', b', c'_2, d'
19. Rotate(C, α, E) → C'_3
20. Rotate(D, α, E) → D'_2
21. Rotate(A, α, E) → A'_1
22. Polygon(C'_3, D'_2, A'_1) → poly2', a', c'_3, d'_1
23. Translate(C, Vector[((α / 180 * 57) * u)]) → C'
24. Translate(C_2, Vector[((α / 180 * 57) * u)]) → T
25. Segment(C', T) → h
26. Segment(A, B) → f
27. Segment(C, C_2) → e
28. Segment(A, B) → i
29. Segment(A, B) → b