# If a circle has a radius of 18 feet, what’s the closest approximation for circumference?

113 feet

Explanation

The formula for figuring circumference of a circle is: $$\text { Circumference }=\text { pi } \times \text { diameter }$$. Diameter = 2r (radius). If we know the radius is 18 feet then Diameter = 18(2)or 36 feet. Therefore, the circumference formula would be: $$C=3.14(\pi) \times 36 \mathrm{ft}=113 \text { feet }$$