It is a deltoid or a kite.
A polygon with 4 or more sides can have a pair of parallel sides.
quadrilateral
polygon
A circle intersected by a pair of parallel lines.
A kite for example.
rhombus
Trapezoid
Any polygon with four or more sides can have a pair of parallel sides. It is also possible to to have non-polygonal shapes - eg a cigar-shape - that has parallel sides.
Any plane polygon having four or more sides may have one pair of parallel sides.
Trapezoid. It has two parallel lines on opposite sides.
Any polygon, other than a triangle, can have one pair of parallel sides.
It might be well it is a rhombus,square,or a rectangle.