Respuesta :

Best that you look up appropriate formulas if in doubt.  The formula for the circumference of a circle is C = 2 pi r.  If r = 4, then C = 2 pi (4) = 8 pi.
Hi!

If the radius is 4 , the diameter is 8 .
Formula = diameter times pi
4 + 4=8
8 times pi = 25.13

Circumference = 25.13

Hope it helps and have a wonderful day!