Since a parallelogram meets with the condition henceall parallelograms are trapezium. Its likeparallelogram is a trapezium with some extra properties. To be a trapezium, Geometric figure should have one pair sides parallel and parallelogramhas two pairs of sides parallel.
A trapezoid is a quadrilateral with at least one pair of parallel sides. In a square, there are always two pairs of parallel sides, so every square is also a trapezoid