If a circle has a diameter of 10 inches, what is the circumference?

2 Answers
Feb 22, 2018

#10pi#

Explanation:

The equation for circumference is #2pir#

You are given the diameter, which is double that of the radius. Therefore, the radius is #10/2=5# inches

Substituting this into the equation will give you
#2pi*5# = #10pi#

Feb 22, 2018

#10pi~~31.4# inches

Explanation:

Circumference of a circle can be given by the equations:

#C=2pir# or #C=pid#

Here, it would be easier for us to use the second equation, as we have the diameter.

#:.C=10pi~~31.4# inches