T1R1I1H4E1D2R1O1N1
13 points
TRIHEDRON is validvalid
a figure having three plane surfaces meeting at a point [n TRIHEDRA, TRIHEDRONS]
a solid figure with three plane surfaces meeting at a point [n TRIHEDRONS or TRIHEDRA]
a figure having three plane surfaces meeting at a point [n TRIHEDRA, TRIHEDRONS]
a solid figure with three plane surfaces meeting at a point [n TRIHEDRONS or TRIHEDRA]