I am not quite sure what you mean, but a "quadrilateral" simply means a "four-sided polygon". There is no requirement that any two sides must be parallel, that any two sides or have the same length, or that any two angles must be equal in measure.
A quadrilateral that has only one pair of parallel sides (the other pair not parallel) is a trapezium.
A quadrilateral with one pair of parallel lines would be a trapezoid. : P
British definition differs with USAUSATrapezoidA quadrilateral with one pair of parallel sidesTrapeziumA quadrilateral with no sides parallelBritishTrapezoidA quadrilateral with no sides parallelTrapeziumA quadrilateral with one pair of parallel sides
No. It can also be a kite.If one pair of adjacent sides of a parallelogramare congruent, then the quadrilateral is a rhombus.
sometimes
Parallel
No, a parallellogram is a quadrilateral with two pair of congruent sides and a trapezoid is a quadrilateral with only one pair of congruent sides.
It could be a kite or an irregular quadrilateral.
trapezoid
Only one pair: trapezium.
For the quadrilateral to be a parallelogram, both pairs of opposite angles must be congruent.
Then, the opposite sides are congruent.