zad 19/20

#include <iostream>

using namespace std;
int a, b,c, p, xa,xb,ya,yb,xc,yc;
int POLE_TROJKATA(int a, int b){

    p=a*b/2;

    return p;

}

int POLE_TROJKATA(int xa, int xb, int ya,int yb,int xc, int yc){


p = (xb-xa)*(yc-ya)-(yb-ya)*(xc-xa)/2;

return p;

}

int main()
{
    cout << "1 - 2 liczby " << endl;
    cout << "2 - wspolrzedne " << endl;
    cin >> c;

    if(c==1){
        cout << "Podaj 2 liczby: " << endl;
        cin >> a;
        cin >> b;
        cout << POLE_TROJKATA(a, b) << endl;
    }
    else if(c==2){
        cout << "Podaj współrzędne(x1,y1,x2,y2,x3,y3): " << endl;
        cin >> xa>>ya>>xb>>yb>>xc>>yc;

        cout << POLE_TROJKATA(xa, xb, ya, yb, xc, yc);

    }
    else{

    }
    cout << POLE_TROJKATA(a, b) << endl;
    return 0;
}