#include <cmath>
#include <cstdio>
#include <iostream>
#include <algorithm>
using namespace std;
const double pi=acos(-1.0);
double f(double a){
	double b=a*pi/180;
	return b;
}
int main(){
  ios :: sync_with_stdio(0), cin.tie(0), cout.tie(0); 
  int T; 
  cin >> T;
  while (T--) {
    double l,i,a,b;
    cin>>l;cin>>i;cin>>a;cin>>b;// printf("%.10lf\n", f(b)); 
    
    double s=(f(a)*(l+i)*(l+i)+f(b)*i*i);
    
    double r=sqrt(l*l+i*i+l*i*2*cos(f(b)));// printf("%.10lf\n", r); 
    double x=acos((i*i+r*r-l*l)/(2*i*r)); // printf("%.10lf\n", x); 
    double q=acos((l*l+r*r-i*i)/(2*l*r));// printf("%.10lf\n", q); 
    double c;
    if(b<=90.0){
      c=0;
    }
    else if(x>=pi/2){
      c=l*i*sin(f(b))-q*r*r;
      double u=f(max(b-90-2*a,0.0));
      c=c-r*r*sin(x)*sin(u)/(sin(pi-x-u))+r*r*u;
    }
    else{
      c=-l*l*sin(f(b))*cos(f(b))-l*l*sin(f(b))*sin(f(b))*f(b-90);// printf("%.10lf\n", f(b-90)); 
      double h=l*sin(f(b));// printf("%.10lf\n",  h); 
      double u=f(max(b-90-2*a,0.0));// printf("%.10lf\n",  u); 
      c=c-h*h*tan(u)+h*h*u; 
    }
    // printf("%.10lf\n",  c); 
    printf("%.15lf\n", s + c); 
  }
	return 0; 
}