In this tutorial, we learn how to solve the circumference with pi. You will first need to know what to equation to figure out circumference is. C= (pi) x (diameter) is what the equation is. So, to figure out the circumference, first figure out what the diameter is. Once you have this, multiply it by pi. This will probably be on your calendar as a symbol, but you can also type it in as 3.14. After you multiply these two numbers together, the number you get is what the circumference is. Make sure to write this out with whatever units you are using, then you will be finished!