All GMAT Math Resources
Example Questions
Example Question #3 : Calculating Circumference
Consider the Circle :
(Figure not drawn to scale.)
Suppose Circle represents a circular pen for Frank's mules. How many meters of fencing does Frank need to build this pen?
We need to figure out the length of fencing needed to surround a circular enclosure, or in other words, the circumference of the circle.
Circumference equation:
Where is our radius, which is in this case. Plug it in and simplify:
And we have our answer!
Example Question #2 : Calculating Circumference
If the radius of a circle is , what is its circumference?
Using the formula for the circumference of a circle, we can plug in the given value for the radius and calculate our solution:
Example Question #8 : Calculating Circumference
Megan, a civil engineer, is designing a roundabout for the city of Madison. She knows that the distance from the edge of the roundabout to the center must be 25 meters. Help Megan find the circumference of the roundabout.
Megan, a civil engineer, is designing a roundabout for the city of Madison. She knows that the distance from the edge of the roundabout to the center must be 25 meters. Help Megan find the circumference of the roundabout.
We are asked to find circumference. In order to do so, look at the following formula:
Where r is our radius and C is our circumference.
We are indirectly told that our radius is 25 meters, plug it in to get our answer:
Example Question #9 : Calculating Circumference
A circle has radius . Give its circumference.
The circumference of a circle is found using the following formula:
Set :