平行线、斜率与共线性的动态几何演示

GeoGebra 命令及参数

1. Line(A, B) → f
2. Line(C, f) → g
3. If(x(E) ≟ x(A), Vector[B, E], Vector[A, E]) → u
4. If(x(E) ≟ x(A), Vector[E, A], Vector[E, B]) → v
5. Point(C, Vector[u + v]) → D
6. Point(C, u) → F
7. Vector(C, F) → w
8. Vector(F, D) → a
9. If(x(E) ≟ x(A), Segment[B, E], Segment[A, E]) → h
10. If(x(E) ≟ x(A), Segment[E, A], Segment[E, B]) → i
11. Text(b + " units", Midpoint[h]) → text1
12. Text(c + " units", Midpoint[i]) → text2
13. Text(text1, Midpoint[C, F]) → text3
14. Text(text2, Midpoint[F, D]) → text4