#include <iostream>

using namespace std;

double kwadrat()
        {
        double pole;
        double b;
        do
        {
               cout << "Podaj dlugosc boku: " << endl;
               cin >> b;
        }
               while(b<=0);
          
        pole = b*b;
        cout << "Pole tego kwadratu wynosi: " << pole << endl;
               
        return pole;
        }
double trojkat()
{
       double pole,a,h;
       do
       {
              cout << "podaj bok trojkata " <<endl;
              cin >> a ;
       }       
              while (a<=0);
       do
       {
              cout << "Podaj wysokosc trojkata " << endl;
              cin >> h;
       }
       while (h<=0);
       
               
       pole = a*h/2;
       cout << "Pole wynosi " << pole << endl;
          
       return pole;           
}

double prostokat ()
       {
       double a,b,pole;
       do
       {
              cout << "Podaj dlugosc 1-go boku: ";
              cin >> a;
       }
              while (a<=0);
       do
       {
              cout << "Podaj dlugosc 2-go boku: " ;
              cin >> b;
       }
              while (b<=0);
                 
       pole = a*b;
       cout << "Pole wynosi " <<pole << endl;
       return pole;
       }
double kolo()
       {
             double pole,r;
             const double pi=3.14;
             do
             {
                          cout << "Podaj dlugosc promienia: ";
                          cin >> r;
             }
                          while(r<=0);
             pole=pi*r*r;
             cout << "Pole wynosi " <<pole << endl;
             return pole;
             system ("cls");
       }      
           
             

int main ()
{
    
    do
    {
         system("cls");
         cout << "Jakiej Figury pole chcesz obliczyc? \n\n";
         cout << " nr 1 - Pole Kwadratu\n nr 2 - Pole Trojkatu\n nr 3 - Pole Prostokata\n nr 4 - Pole Kola\n nr 0 - Wyjscie!\n" ;
         cout << endl;
         char ktore;
         cin >> ktore ;
    
    
    switch(ktore)
    {
             case '1':
                  system("cls");
                  cout << "Wybrales Pole Kwadratu\n\n";
                  kwadrat();
                  system ("pause");
                  break;
                  
             case '2':
                  system("cls");
                  cout << "Wybrales Pole Trojkatu\n\n";
                  trojkat();
                  system ("pause");                 
                  break;
             case '3':
                  system("cls");
                  cout << "Wybrales Pole Prostokata\n\n";
                  prostokat ();
                  system ("pause");
                  break;
             case '4':
                  system("cls");
                  cout << "Wybrales Pole Kola\n\n";
                  kolo ();   
             case '0':  
                  return 0;   
           
             default:
                     cout << "Wybrales zly klawisz! " << ktore << " nie znam takiego! \n";
                     break;
    }
    }
    
    while(1);

}