CPP Program to Calculate Circumference of Circle

//Write a program to calculate circumference of circle.

#include<iostream.h>

#include<conio.h>

void main()

{

 clrscr();

 float r,cir;

 cout<<"Enter radius -";

 cin>>r;

 cir=2*3.14*r;

 cout<<"Circumference of circle -"<<cir;

 getch();

}

Output: