Difficulty: Easy
Instructions
Things You'll Need:
- calculator
-
Step 1
In order to calculate circumference of a circle, you must first determine the diameter of the circle. If you already know the radius of the circle, multiply the radius by 2 to get the diameter.
-
Step 2
Use the following formula to find the circumference of a circle:
c = π * d
or
c = 2π * r
or
c = π * 2r
where:
c = circumference
π = Greek letter "pi" = 3.14 (if your calculator does not have a π button, but use the button for π if you have it -- π is the ratio of a circle's circumference to its diameter)
d = diameter
r = radius -
Step 3
Example problem to calculate circumference of a circle:
A circle has a radius of 7.6 feet. Therefore:
c = π * (2)(7.6)
c = π * 15.2
circumference = 47.8 feet
