Pi = circumference/diameter
Formulas relating to circles
All around the world, because pi is used in many formulas.
They are: 2*pi*radius or as diameter*pi
u0/4
πr2 2πr
the other formulas involve non-circular shapes
If you mean the following:- Circumference of circle: 2*pi*radius Area of circle: pi*radius^2 The above formulas are only approximates because the exact value of pi has never been finally determined because pi is an irrational number.
C= 2 times pi and C= pi times diameter C= 2 times pi and C= pi times diameter
the other formulas involve non-circular shapes
C=Pi*D
C = 2*pi*rC = pi * dwhere d = diameter and r = radiusSince d = 2r by definition, the formulas are equivilent