circumference = 2*pi*radius or pi*diameter
It is an arc
The circumference of a circle = pi*diametre = 2pi*radius
The equator.
Then they are similar.
Pi times the diameter of a circle gives its circumference.
The ratio of the circumference of a circle to its diameter is Pi. (3.14159)
It is part of a curve. If that curve happens to be a circle, then it is a fraction of a circumference but it need not be.
Okay, for starters, circumference is used only for circles and spheres. the UK is neither so therefore it has no circumference.
Any circle's circumference can be calculated with the formula 2(pi)*radius
Circumference is a special name for a circles perimeter. I think the answer you are looking for is radious.
In circles the circumference is 3.14 (pi) times the Diameter.