A pair of opposite sides is parallel.name the quadrilateral property

If you are talking about quadrilaterals so first we should know it's meaning and here it is:
definition of quadrilaterals: it is a figure made up of 4 line segments.
Now coming on to the question name the figures whose one pair of opposite sides are equal so here they are square , rectangle , parallelogram and trapezium.
(But you can think that how square ,rectangle and parallelogram have only one pair of opposite sides and if you talk about this so in these quadrilaterals you can count any one)
regards
hope this helps!