Rhombus (a special case of a parallelogram, and it is a four-sided quadrilateral. In a rhombus, opposite sides are parallel and the opposite angles are equal.)
Square (a quadrilateral with 4 congruent sides and 4 right angles, and they also have two sets of parallel sides.)
Parallelogram (a quadrilateral with two sets of parallel sides)
Trapezoid ( a quadrilateral with one pair of opposite sides parallel.)
