1. ''Tri"
Three
by Irene

2. Tricycle A three wheeled bicycle.
                    
 Jessica learned how to ride a tricycle and rode it everywhere.

3. Tripod The teacher sat down and put her coffee on a tripod.
                A stool or table that has three legs. 
The teacher sat down and put her coffee on a tripod.

4. Any similar groups or three.
Triplets
Any similar groups or three.
Three girls dressed up as triplets to fool who was who.

5. Tom divided the year into a trimester.
A time of 3 months.
Tom divided the year into a trimester.

6. Trilobite
An extinct fossil with it's skeleton divided into 3 parts.
Mark researched the trilobite as he was looking at other fossils.

7. References http://dictionary.reference.com/browse/tricycle