
Let D be the midpoint of line segment AC.
Let E be simultaneously the midpoint of line segments CB and DF.
Please note that the rightmost point is labeled F.
Goal: Using vector analysis proof that quadrilateral [ABFD] is in fact a paralelogram.
any hints?
Vectorially,$$\vec{BF}=\vec{BE}+\vec{EF}=\vec{EC}+\vec{DE}=\vec{DC}=\vec{AD}.$$