-hedral

-hedral

suff. Having a specified kind or number of surfaces: dihedral.
[From -hedron.]

-hedron

a combining form used in the names of geometrical solid figures having the form or number of faces specified by the initial element: tetrahedron. [< Greek -edron, neuter of -edros having bases, -sided, derivative of hédra seat, face of a geometrical form (compare cathedra)]