Given a parallelogram ABCD,
Since it is a parallelogram,
[tex]\begin{gathered} \bar{AB}=\bar{CD} \\ \bar{AD}=\bar{BC} \end{gathered}[/tex]
Also,
[tex]\bar{AB}\parallel\bar{CD}[/tex]
Therefore, the line segment parallel to CD passing through A , must fall on AB.
