The circumference of a circle is 6.28 meters. what is the circle's radius? c=6.28 m use 3.14 for pi

C = 2pi*r
Plug in the circumference
6.28 = 2*pi*r
3.14 = pi *r 
plug in pi
3.14 = 3.14 * r
r = 1

In this exercise it is asked to find the radius of a circle with a circumference of 6.28 meters. The formula to find the circumference or perimeter of a circle is C=2πr, where r represents the radius of the circle.

In this case that is already given the circumference, you have to solve the previous formula for r, and of this form the circle's radius could be find.
  
C=2πr        Divide in both sides by 2π to isolate r
C/2π=r

Now you can find the value of the radius by using the formula r=C/2π  and substituting the values of the circumference ans pi.

r=C/2π
r=6.28/2(3.14)
r=6.28/6.28
r= 1 meter

The circle's radius is 1 meter.