T1E1T1R1A1H4E1D2R1O1N1
15 points
TETRAHEDRON is validvalid
a polyhedron with four sides [n TETRAHEDRA, TETRAHEDRONS]
a polyhedron that has four faces [n TETRAHEDRA or TETRAHEDRONS]
a polyhedron with four sides [n TETRAHEDRA, TETRAHEDRONS]
a polyhedron that has four faces [n TETRAHEDRA or TETRAHEDRONS]