#include<iostream>

using namespace std;

int showmenu();

float area(double rad);

float area(float side);

float area(float length, float width);

void main()

{

int x;

float arr, side, length, width;

double radius;

x = showmenu();

if (x == 1)

{

cout << "Enter the radius of the circle: ";

cin >> radius;

arr = area(radius);

}

else if (x == 2)

{

cout << "Enter the length of the side of the sqaure: ";

cin >> side;

arr = area(side);

}

else if (x == 3)

{

cout << "Enter the length of the side of the rectangle: ";

cin >> length;

cout << "Enter the width of the side of the rectangle: ";

cin >> width;

arr = area(length, width);

}

else

{

cout << "Incorrect choice" << endl;

return;

}

cout << "Area = " << arr << endl;

system("pause");

}

int showmenu()

{

int ch;

cout << "Enter 1 to calculate area of a circle." << endl;

cout << "Enter 2 to calculate area of a square." << endl;

cout << "Enter 3 to calculate area of a rectangle." << endl;

cout << "Enter your choice: ";

cin >> ch;

return ch;

}

float area(double rad)

{

float area;

area = (22 * rad * rad) / 7;

return area;

}

float area(float side)

{

float area;

area = side * side;

return area;

}

float area(float length, float width)

{

float area;

area = length * width;

return area;

}