It is the formula for finding the circumference of a circle which is the same as 2*pi*radius
The formula to find the circumference of a circle is Pi X D where D is Diameter and Pi is 3.1416.
((pi*d Outside)-(pi*d inside))/2
d * pi or 2 * r * pi Where d is diameter and r is radius and pi = 3.14159
C = d x Pi, where d is the diameter and Pi is about 3.1416
pi = C / d C = pi times d d = C / pi
d * pi or 2 * r * pi Where d is diameter and r is radius and pi = 3.14159
d * pi or 2 * r * pi Where d is diameter and r is radius and pi = 3.14159
d * pi or 2 * r * pi Where d is diameter and r is radius and pi = 3.14159
d * pi or 2 * r * pi Where d is diameter and r is radius and pi = 3.14159
d * pi or 2 * r * pi Where d is diameter and r is radius and pi = 3.14159
C=2"pi"r C=d"pi"
Circumference = pi*d where d is the diameter.