Circumference of Circle C++ Example Program in C++

About this program

This is an example program in c common example program. Read the concept first: C++ Variables and Data Types, then study the code and output below.

Definition

When a circle’s diameter is 1, its circumference is π. When a circle’s radius is 1—called a unit circle—its circumference is 2π.

Formula

The circumference of a circle is written

π = C / d

Or, equivalently, as the ratio of the circumference to twice the radius. The above formula can be rearranged to solve for the circumference:

C = π * d = 2π * r

here,

r = Radius
π = ~3.14

Circumference Of Circle Example Program

/*## Circumference Of Circle In C++*/
/*## Calculation C++ Programs, Datatype C++ Programs, Basic C++ Programs*/

#include <iostream>
#include<conio.h>
#include<stdlib.h>

using namespace std;

float PI = 3.14;

int main() {
   // Declare Variables
   float radius, ci;

   cout << "Simple C++ Program : Circumference Of Circle\n";
   cout << "\nEnter the radius of Circle : ";
   cin>>radius;

   ci = 2 * PI * radius;

   cout << "\nCircumference of Circle : " << ci;

   getch();
   return (0);
}

Sample Output

Simple C++ Program : Circumference Of Circle

Enter the radius of Circle : 5

Circumference of Circle : 31.4

Related Pages

Learn the concept first, then study the code:

• C++ Programs — Browse all C++ Programs.
• C++ Variables and Data Types — Tutorial — data types and variable declaration.
• Factorial Using Loop Example Program In C++ — More in c common example program.
• Factorial Using Function Example Program In C++ — More in c common example program.