A pentagon is a 2-D shape. There is a 3-D shape with 12 faces, each a regular pentagon. It's called a dodecahedron.
To make one out of (stiff) paper, you would cut out a "net", then fold and glue the edges.
See related link for an illustration of a net you could print out.
Paper is a 3D object.
pentagon
A piece of paper is 3D.
pentagon
Dodecahedron.
Pentagon 2d shape is a pentagon 3d object is a pyramid.
3D
a 3D pentagon
a pentagonal pyramid or a pentagonal prisim
A flat pentagon. Or some kind of circle pentagon breed...
A pentagonal pyramid.
It's a Pentagonal Prism or Pyramid.