PRISMS
Prisms comprise a family of semiregular polyhedra;
the ends of the prism are identical regular polygons,
with corresponding sides ``attached'' with squares.
In general the end-polygons can be convex or can
be stars. Examples:
Convex prisms
Triangular prism,
``square prism'' (cube),
pentagonal prism,
hexagonal prism,
heptagonal prism,
octagonal prism:
etc.
Nonconvex prisms
Pentagrammatic prism:
................
Heptagrammatic (7:2) prism:
................
Heptagrammatic (7:3) prism:
................
etc.