Uni, bi, tri, quad

A mythical animal represented as a horse with one horn. 

• Unicycle
• Bicycle
• Unicorn
• Tricycle

A large muscle in the front of the thigh divided into four portions. 

• Quadrilateral
• Bifocals
• Unicorn
• Quadriceps

Same clothing worn by members of the same organization or team.

• Unicycle
• Uniform
• Triathlon
• Quadriceps

A four sided figure.

• Quadrilateral 
• Bifocals
• Triangle
• Tricycle

A cycle with one wheel

• Tricycle
• Bicylce
• Unicycle
• Triathlon

An athletic event consisting of three events. 

• Tricycle
• Bicycle
• Triathlon
• Quadrilateral 

A vehicle with two wheels propelled by pedals and a handle bar. 

• Tricycle
• Bicycle
• UNicycle
• Unicorn

A vehicle with 3 wheels. 

• Tricycle
• Bicycle
• Unicycle
• Car

A figure with three sides and three angles.

• Square
• Triangle
• Line
• Octagon

A pair of eyeglasses with two parts

• Glasses
• Unicorn
• Bifocals
• Quadrilateral