Answer:
The distance around a rectangle or a square is as you might remember called the perimeter. The distance around a circle on the other hand is called the circumference (c). A line that is drawn straight through the midpoint of a circle and that has its end points on the circle border is called the diameter (d)
Explanation:
The formula is simply this: C = πd. In this equation, "C" represents the circumference of the circle, and "d" represents its diameter. That is to say, you can find the circumference of a circle just by multiplying the diameter by pi.
Calculating the circumference of a circle (Pre-Algebra, More)