WHAT is a prism?The different shapes that make a prism and finally what prism can you make with a pentagon base?
http://en.wikipedia.org/wiki/Prism_%28geometry%29
and
http://www.google.com/images?hl=en&q=prism&um=1&ie=UTF-8&source=og&sa=N&tab=wi
How can you describe the images you see in these websites?