#include <iostream>
#include <string>
#include <cstdlib>
#include <stdio.h>
#include <cmath>
#define PI 3.141592653
using namespace std;

int main()
{
    int T;
    double x1, y1, x2, y2;
    double a,b,cosx, arcosx;
    cin >> T;
    while (T--)
    {
        cin >> x1 >> y1 >> x2 >> y2;
        a = x1*x2 + y1*y2;
        b = sqrt((x1*x1 + y1*y1)*(x2*x2 + y2*y2));
        cosx = a / b;
        arcosx = acos(cosx) /PI *180;
        printf("%.2lf\n", arcosx);
    }
    return 0;
}