quadrilateral: 4 coplanar sides and 4 angles whose measure add up to 360
parallelogram: Quadrilateral attributes AND both paris of sodas are parallel, opposite angles are congruent, consecutive angles are supplementary, diagonals bisect each other and opposite sides are congruent
parallelogram: Quadrilateral attributes AND both paris of sodas are parallel, opposite angles are congruent, consecutive angles are supplementary, diagonals bisect each other and opposite sides are congruent