In order to calculate the diameter of the circle must know the length or area. If we know one of the ukazannh values will not be difficult to calculate the diameter of the circle for us.
The diameter of the circle is calculated using the following formulas:
Where D  diameter of the circle, S  area of a circle, P  the length of the circle, R  radius, π  Pi is always approximately equal to 3.14.
The diameter of the circle through its length 

The diameter of the circle through the area 

The diameter of the circle through the radius 
