Answer :
Parallelograms and trapezoids always do.
(Note: "Parallelograms" includes rectangles, squares, and rhombussesses.)
Any polygon with more than 4 sides can have at least one pair of parallel sides,
but it's not guaranteed.
(Note: "Parallelograms" includes rectangles, squares, and rhombussesses.)
Any polygon with more than 4 sides can have at least one pair of parallel sides,
but it's not guaranteed.
