A parallelogram has opposite sides that are parallel. Squares, rectangles and rhombi are parallelograms with four right angles and are known as quadrilaterals.
A polygon is a two dimensional shape with straight sides.
Therefore polygons that are also parallelograms are quadrilaterals.
Trapezoids (A and J are "typical" examples, but all parallelograms also fit the definition of trapezoids);parallelograms (E is the "typical" example, but all rectangles and rhombuses also fit the definition of parallelograms);rectangles (F is the "typical" example, but all squares also fit the definition of rectangles);rhombuses (C and D are the "typical" examples, but all squares also fit the definition of rhombuses);squares (B), the most special of them all
