Prismatic surface
In solid geometry, a prismatic surface is a polyhedral surface
generated by all the lines that are parallel to a given line and that intersect a polygonal chain in a plane that is not parallel to the given line.{{citation|title=Solid Geometry|first1=Mabel|last1=Sykes|first2=Clarence E.|last2=Comstock|publisher=Rand McNally & Company|page=49|year=1922|url=https://archive.org/details/solidgeometry00sykerich/page/48}} The polygonal chain is the directrix of the surface; the parallel lines are its generators (or elements). If the directrix is a convex polygon, then the surface is a closed prismatic surface. The part of a closed prismatic surface between two parallel copies of the directrix is a prism.{{citation|title=Solid Geometry with Problems and Applications|first1=H. E.|last1=Slaught|first2=N. J.|last2=Lennes|publisher=Allyn & Bacon|year=1911|page=34|url=https://archive.org/details/solidgeometrywit00slaurich/page/32}}