How do you solve radius with 6in?

If the radius is 6 inches, you can do a couple different things. You can do 3.14 times 6 then double it. Or you can do 6.28 times 6. Either way it comes to the answer, 37.68 inches is the cicumference. You can also double the radius to make it the diameter (12) and multiply by 3.14 to get the same answer: 37.68. The formula is C=rpie2 or C=dpie. So for this problem you would do C=6 times 3.14 times 2. Then substitute in for the variables until you solve it all. Good luck!