Area of Circle

Write a program in C++ to calculate area of a circle taking input 'radius' from user.

/*Program 2

Date : 20 - March - 2019

Program Name: Calculate area of a circle

Class : XI

Developed By : Aditi Bhushan*/

#include <iostream>

using namespace std;

float circleArea(float);

float circleArea(float r)

{

// defining the function

const float pi = 3.14;

float area;

area = pi * r * r;

return area;

}

int main()

{

float radius;

cout << "Enter radius of the cicle: \t";

cin >> radius;

cout << "\n\nThe Area of cicle is ";

cout << circleArea(radius) <<" cm.sq.\n"; //declaring the function

return 0;

}