2
1 1 2 2
1 1 1 0

0.00
45.00                                                                                                                                  
#include<math.h>
#include<stdio.h>
const double Pi=3.14159;
int main()
{
        int n;
        double x1,y1,x2,y2;
        scanf("%d",&n);
        while(n--)
        {
                scanf("%lf %lf %lf %lf",&x1,&y1,&x2,&y2);
                printf("%.2f\n", (acos( (x1*x1 + y1*y1 + x2*x2 + y2*y2- (x1-x2)*(x1-x2) - (y1-y2)*(y1-y2) )/(2* sqrt(x1*x1 + y1*y1) * sqrt(x2*x2 + y2*y2) )))*180/Pi);
        }
        return 0;
}