Quadrilateral rstu has one pair of opposite parallel sides and one pair of opposite congruent sides as shown. based on the given information, which statement best explains whether the quadrilateral is a parallelogram? it cannot be determined from the information given. it is not a parallelogram because the congruent sides cannot be parallel. it is not a parallelogram because the parallel sides cannot be congruent. it is a parallelogram based on the single opposite side pair theorem.