Pentagon.
http://wiki.answers.com/Q/What_is_a_shape_with_5_s...

Pentagon is a fivesided polygon. ChaCha again, we'll be here!
http://www.chacha.com/question/whatisashapewit...

A tetrahedron is one of the five Platonic solids, since it is a pyramid made up of four equal triangles. But a squarebottomed pyramid is not a tetrahedron, since it also includes
http://www.ehow.com/info_8510888_shapessidessqua...

There are all sorts of possible shapes. I have got cuboid vases (rectangular sides) nearspherical vases (circular sides) ovoid or ellipsoidal vases (oval or ellipse sides) ellipsoid
http://wiki.answers.com/Q/What_is_the_shape_of_the...
