1. Find the diameter of a
circle if the radius is 3 in. 

Why? 
2. Find the radius of a
circle if diameter is 20 cm. 

Why? 
3. If the diameter of a
ball is 6", what is the circumference?
Round to the nearest whole number. 

Why? 
4.
To the nearest whole number, what is the circumference of a circular
race track, if the
diameter of the race track is 125 meters? 

Why? 
5.
If the radius of the pool is 12 feet what is the circumference?
Round to the nearest whole number. 

Why? 