G_8.07 三角形面积与几何构造

GeoGebra 命令及参数

1. Polygon(A, B, C) → poly1, c_2, a, b_3
2. Midpoint(b_3) → D
3. Segment(A, D) → i
4. Segment(D, C) → j
5. Segment(C, B) → k
6. Segment(B, A) → l
7. Line(B, C) → f
8. Line(B, A) → h_1
9. Line(A, C) → n
10. OrthogonalLine(A, f) → p
11. OrthogonalLine(B, n) → q
12. OrthogonalLine(C, h_1) → r
13. Intersect(f, p) → E
14. Intersect(n, q) → F
15. Intersect(h_1, r) → G
16. Dilate(A, If[0 < d ≤ 1, 1 - d, 0], E) → A'_1
17. Segment(A, A'_1) → h
18. Polygon(B, E, A) → poly2, a_1, b_1, e
19. Polygon(E, A, C) → poly3, c_1, e_1, a_2
20. Angle(A, E, B) → β
21. Polygon(B, E, A) → poly4, a_3, b_2, e_2
22. Dilate(B, If[0 < d ≤ 1, 1 - d, 0], E) → B'_1
23. Dilate(B, If[0 < d ≤ 1, 1 - d, 0], A) → B'_2
24. Segment(B, B'_1) → h_2
25. Segment(B, B'_2) → c
26. Segment(A, C) → b
27. Angle(A, E, B) → γ