Answer:
Always
Step-by-step explanation:
A parallelogram by definition is a closed shape with two pairs of parallel sides, no more, no less.
A quadrilateral by definition is a closed shape with four sides.
No matter what parallelogram you have, it will always have four sides, because it will always have two pairs of parallel sides. Two sides are needed to make a set of parallel sides, and two times two is four.
A quadrilateral is a closed shape with four sides, so a parallelogram is always a quadrilateral.
