#include <iostream>
#include <fstream>
int trojkat(int a, int h) 
{
	int d;
	d=(a*h)/2;
	return d;
}
int kwadrat(int a)
{
int d;	
d=a*a;
return d;
}
int prostokat(int a, int b){
int d;
d=a*b;
return d;	
}
int rownoleglobok(int a, int h)
{
int d;
d=a*h;
return d;		
}
int trapez(int a, int b,int h){

int d;
d=a+b/2*h;
return d;
}
using namespace std;
int main(){
int wybor,b ,a,h;
cout<<"1 trojkat,2 kwadrat,3 prostokat,4 rownoleglobok,5 trapez"<<endl;
cin>>wybor;
switch(wybor)

{
case 1:
	cout<<"podaj a:";
	cin>>a;
	cout<<"podaj h:";
	cin>>h;
  cout<<"pole trojkatu="<<trojkat(a,h)<<endl;
    break;
   
case 2:
 cout<<"podaj a:";
 cin>>a;
 cout<<"pole kwadratu="<<kwadrat(a)<<endl;  
    break;
   
  
case 3:
  cout<<"podaj a";
  cin>>a;
  cout<<"podaj b";
  cin>>b;
  cout<<"pole prostokatu"<<prostokat(a,b)<<endl;
    break;
    
    
case 4:
	cout<<"podaj a";
	cin>>a;
	cout<<"podaj h";
	cin>>h;
	cout<<"pole rownolegloboku="<<rownoleglobok(a,h)<<endl;
  
    break;
case 5:
	cout<<"podaj a";
	cin>>a;
	cout<<"podaj b";
	cin>>b;
	cout<<"podaj h";
	cin>>h;
	cout<<"pole trapezu="<<trapez(a,b,h)<<endl;
    
  break;
   

}    

return 0;
}