25.12 in or 8π
Step-by-step explanation:
Since you didn't specify whether or not to leave pi or to make it be 3.14, I did both.
The formula for the circumference of a circle is...
[tex]C=2\pi r[/tex]
So...
[tex]C=2*3.14*4[/tex]
C = 25.12 in
If you want to leave pi...
[tex]C=2*\pi *4[/tex]
C = 8π