Here are some common ones:
triad
triage
trial
triangle
triangular
triathlon
tribal
tribe
tribesman
tribulation
tribunal
tribune
tributary
tribute
trice
triceps
trick
trickery
trickiness
trickle
trickster
tricky
tricolor
tricycle
trident
tried
triennial
trifle
trifling
trig
trigger
trigonometry
trill
trillion
trillionth
trilogy
trim
trimaran
trimester
trimly
trimmer
trimming
trimmings
trimness
trinket
trio
trip
tripartite
tripe
triple
triplet
triplicate
tripod
triptych
trisect
trite
tritely
triteness
triumph
triumphal
triumphant
triumphantly
triumvirate
trivet
trivia
trivial
triviality
trivialize
triangle tricycle triplet trillion triple trio tripod
tricycle
trigonometry
triple
triplets
tripod
triangle
triangle
triathlon
tricycle
triangle, triginometry
BibilingualbivalvebipedalbisectbicycleTritriangletriumviratetripletrisecttriangle
triplet
tria 'tree-uh' is Greek for the number 3
Tri Pod Cycle
triceps
There are words that Begin with the prefix tri- like: Triangle, Tripod, Tricycle, and Triceratops
tri tripod
tricycle trinomial tridium triangle tri triangular trial triple
Trim, trip.
Three
triangle, trim,
triple, tricycle, triathlon, triangle, trimonthly, trilogy, tricolor, triceratops, tri-state area,