if u are referring to explaining how to solve the circumference of circle,To calculate the circumference of a circle, multiply the diameter of the circle with π (pi). The circumference can also be calculated by multiplying 2×radius with pi (π=3.14). or in other words, The formula for the circumference of a circle is C = 2πr, where r is the radius. to find the radius, u must find the diameter and divide that number by 2. from there is would be 2 times r(radius) times pi