To answer this question we need to remember some properties for any parallelogram:
• Two pairs of opposite sides are equal in length.
,• Two pairs of opposite angles are equal in measure.
,• The diagonals bisect each other.
We notice that in the figure QSRP opposite sides are equal in length then we conclude that this is a parallelogram.
In figure RSUT we notice that the diagonals bisect each otherm then we conclude that this is a parallelogram.
In figure KLNM we notice that none of the properties stated before are fullfill, then this is not necesarrily a parallelogram.
In figure BDCA we notice that alternate interior angles are equal, this means that segments BD and CA are parallel, we also notice that the other segments are parallel; therefore this is a parallelogram.
