### What is a 3d quadrilateral with one pair of parallel sides?

A quadrilateral is a plane or 2d figure with four sides. A 3d shape (object) has a name ending with -hedron, eg a tetrahedron which is a four sided 3d shape. A 3d quadrilateral has no meaning. Sides (edges) do exist in 3d shapes, but a more pertinent attribute is faces. Do you mean by "3d quadrilateral" a 3d shape which has a quadrilateral as a base and at most 4 or 5 other sides…