M


 * "M" redirects here. For the Stewart toroid M, see Tortuous tunnel.

m is a non-convex polyhedron with regular faces.

Related polytopes
Despite not having any pentagonal faces, m is related to two 5-4-3 acrohedra. m can be augmented by a pentagonal pyramid to form m*, the smallest 5-4-3 acrohedron by face count. Two copies of m can be excavated from A5 '' to form the prize substitute.