Respuesta :

Hello!

To find the circumference of a circle you multiply its diameter by pi. Usually people round pi, (which is irrational) to 3.14, Therefore we will multiply our diameter by 3.14.

4(3.14)=12.56

12.56 units is our circumference.

I hope this helps!
ASHLEYISLANDS
The answer is 12 .57 

how to solve it 
2x pi x r ( radius )
plug in the numbers since you have a diameter split it in half to get the radius .