Circumfrence is to a circle as perimeter is to a polygon. The circumfrence of a circle always equals the diameter (or two times the radius, since the radius is half of the diameter) times pi.
The circumfrence would be 7926.41π miles because of this. Should you round pi to 3.14, the circumfrence would be 7926.41 * 3.14. This is equal to <span>24888.9274 miles. (round that if needed)</span>
20y^7. this is because the exponents are added together because the variable attached to the coefficient are the same therefor the coefficients are multiplied, and the exponents are added together.
