prog14.cpp

/*
Write a C++ Program to compute the area of a circle, triangle and rectangle
using function overloading.
*/

#include <cmath>
#include <iostream>

using namespace std;

class Shape {
public:
  float area(float r) { return M_PI * pow(r, 2); }

  float area(float l, float w) { return l * w; }

  double area(float a, float b, float c) {
    double s = (a + b + c) / 2;
    double x = s * (s - a) * (s - b) * (s - c);

    return sqrt(x);
  }
};

int main() {
  float r, l, w, a, b, c;
  Shape s;

  cout << "Enter radius: ";
  cin >> r;
  cout << "Area of Circle: " << s.area(r) << endl;

  cout << "Enter length and width" << endl;
  cin >> l >> w;
  cout << "Area of Rectangle: " << s.area(l, w) << endl;

  cout << "Enter three sides (Triangle)" << endl;
  cin >> a >> b >> c;
  if (a + b > c && a + c > b && b + c > a) {
    cout << "Area of Triangle: " << s.area(a, b, c) << endl;
  } else {
    cout << "Invalid triangle" << endl;
  }

  return 0;
}