Program to find Circumference of a Circle

Given radius of a circle, write a program to find its circumference.
Examples : 
 

Input : 2
Output : Circumference = 12.566

Input : 8
Output : Circumference = 50.264

 

In a circle, points lie in the boundary of a circle are at same distance from its center. This distance is called radius. Circumference of a circle can simply be evaluated using following formula. 
 

Circumference = 2*pi*r
where r is the radius of circle 
and value of pi = 3.1415.

 

👁 Image

 

Output : 

Circumference = 31.415

Time Complexity: O(1), since there is no loop or recursion.

Auxiliary Space: O(1), since no extra space has been taken.

This article is contributed by Saloni Gupta .