The diameter of a pizza is 14 inches. What is the circumference of the pizza? Tell you what value you used for pi
The formula for finding circumference is C=2*pi*r. So C is the circumference that you are trying to find. Pi is 3.14. And r is the radius. Now, it does not tell you directly what the radius is, but the diameter of a circle is basically how far across is it. So in this case, 14. The radius of a circle is half of it's diameter, so half of 14 is 7. So, multiply 2*3.14*7, to get the circumference. You get 43.96.