Program to find Circumference of a Circle

11 Jul, 2022
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.
 
 
C++
Java
Python3
C#
PHP
Javascript
// CPP program to find circumference of circle#include<bits/stdc++.h>using namespace std; #define PI 3.1415 double circumference(double r){    double cir = 2*PI*r;    return cir;} // driver functionint main(){  double r = 5;  cout << "Circumference = "       << circumference(r);  return 0;}
// Java program to find circumference of circleimport java.io.*; class Geometry {         // utility function    static double circumference(double r){         double PI = 3.1415;        double cir = 2*PI*r;        return cir;    }         // driver function    public static void main (String[] args) {         double r = 5;        double result = Math.round(circumference(r) * 1000) / 1000.0;        System.out.println("Circumference = "+ result);    }} // This article is contributed by Chinmoy Lenka
# Python3 code to find# circumference of circle PI = 3.1415 # utility functiondef circumference(r):    return (2 * PI * r)  # driver functionprint ('%.3f' % circumference(5)) # This code is contributed by Saloni Gupta
// C# program to find circumference of circleusing System; class GFG {         // utility function    static double circumference(double r){         double PI = 3.1415;        double cir = 2*PI*r;        return cir;    }         // driver function    public static void Main () {         double r = 5;        double result =              Math.Round(circumference(r)                        * 1000) / 1000.0;                                 Console.WriteLine("Circumference = "                                  + result);    }} // This article is contributed by anuj_67.
<?php// PHP program to find// circumference of circle $PI= 3.1415; function circumference($r){    global $PI;    $cir = 2 * $PI * $r;    return $cir;} // Driver Code$r = 5;echo "Circumference = ",circumference($r); // This code is contributed aj_36?>
<script> // Javascript program to find circumference of circle function circumference(r){    let cir = 2*3.1415*r;    return cir;} // driver function  let r = 5;document.write("Circumference = "    + circumference(r)); //This code is contributed by Manoj </script>
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.
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