There are 10 words that start with 'trih'.
| trihedra | trihedral |
| trihedron | trihybrid |
| trihedrals | trihedrons |
| trihybrids | trihydroxy |
| trihalomethane | trihalomethanes |
Note: These 10 words that start with 'trih' are found from the USA & Canada version of the tournament Scrabble word list.