The shape has a constant cross section. It is a prism.The cross-section is a pentagon.The 3D shape is a pentagonal prism. For all polyhedra the number of edges is two less than the sum of the ...

A prism with a pentagon-shaped cross-section is a pentagonal prism. A 3D shape with a circular cross-section is a cylinder. A cylinder is not a prism because the circle is not a polygon.