三角形面积 by Malin Christersson

GeoGebra 命令及参数

1. Line(A, B) → a
2. OrthogonalLine(B, a) → b
3. Point(b) → C
4. Polygon(A, B, C) → poly1, c, a_1, b_1
5. OrthogonalLine(C, a_1) → d
6. OrthogonalLine(A, c) → e
7. Intersect(d, e) → D
8. Polygon(A, B, C, D) → poly2, a_2, b_2, c_1, d_1
9. Line(E, F) → f
10. OrthogonalLine(F, f) → g
11. Point(g) → G
12. OrthogonalLine(G, g) → h
13. OrthogonalLine(E, f) → i
14. Intersect(h, i) → H
15. Polygon(E, F, G, H) → poly3, e_1, f_1, g_1, h_1
16. Point(g_1) → I
17. Polygon(E, F, I) → poly4, i_1, e_2, f_2
18. OrthogonalLine(I, e_1) → p
19. Intersect(p, e_1) → N
20. Segment(I, N) → hSeg
21. Polygon(J, K, L) → poly5, l, j, k
22. Line(J, j) → m
23. Line(L, l) → n
24. Intersect(m, n) → M
25. Polygon(J, K, L, M) → poly6, j_1, k_1, l_1, m_1
26. Angle(C, B, A) → β
27. Midpoint(hSeg) → mid
28. Text("h", mid + (0.1, 0)) → hText
29. Midpoint(E, F) → mid2
30. Text("b", mid2 + ((-0.05), (-0.12))) → bText