LIGHTOJ 1305 - Area of a Parallelogram

#include<bits/stdc++.h>
using namespace std;
int main()
{
    int ax,ay,bx,by,cx,cy,dx,dy,t,i=0;
    double a,b,x,thita,h,area;
    scanf("%d",&t);
    while(t-- && scanf("%d%d%d%d%d%d",&ax,&ay,&bx,&by,&cx,&cy)==6)
    {
        dx=cx-bx+ax;
        dy=cy-by+ay;
        a=(double)sqrt(((dx-ax)*(dx-ax))+((dy-ay)*(dy-ay)));
        b=(double)sqrt(((ax-bx)*(ax-bx))+((ay-by)*(ay-by)));
        x=(double)sqrt(((dx-bx)*(dx-bx))+((dy-by)*(dy-by)));
        thita=acos(((x*x)+(b*b)-(a*a))/(2*x*b));
        h=x*sin(thita);
        area=b*h;
        printf("Case %d: %d %d %.0lf\n",++i,dx,dy,area);

    }

    return 0;

}