#include<bits/stdc++.h>

using namespace std;
typedef long long ll;
constexpr double eps = 1e-7;
constexpr double PI = acos(-1);
bool eq(double a, double b) { return abs(a - b) < eps; } // ==
bool gt(double a, double b) { return a - b > eps; }      // >
bool lt(double a, double b) { return a - b < -eps; }     // <
bool ge(double a, double b) { return a - b > -eps; }     // >=
bool le(double a, double b) { return a - b < eps; }      // <=
double calc(double l1,double _l3,double __l3,double _R,double A){
    return l1 * _l3 * sin(_R) - _l3 * _l3 * 2 * A - _l3 * __l3 * sin(_R - 2 * A);
}
void solve(){
    int p,q,a,b;
    double l1,l2;
    cin >> p >> q >> a >> b;

    l1 = p;l2 = q;

    double A = PI * (double)a / 180;

    double B = PI * (double)b / 180;

    double ans = 1.0 * (l1 + l2) * (l1 + l2) * A + 1.0 * l2 * l2 * B;
    

    if(b <= 90){
        cout << fixed << setprecision(12) << ans << "\n";return ;
    }else {
        cout << fixed << setprecision(12);
        double l3 = sqrt(1.0 * l1 * l1 + 1.0 * l2 * l2 + 2 * l1 * l2 * cos(B));
        double R = asin(sin(B) * l2 / l3);
        double C = PI - (PI - B) - R;
        //cout  << 180 * C / PI << "\n";

        if(ge(2 * C,PI)){
            //cout << "aa";
            
            //cout << l3 << "\n";
            if(ge(2 * A,R)){
                double s = l1 * l2 * sin(B) - l3 * l3 * R;
                //cout << ans << "\n";
                ans += s;
                cout << ans << "\n";
            }else {
                double _C = PI - (PI - B) - 2 * A;
                double _l3 = l1 * sin(B) / sin(_C);
                ans += calc(l1,l3,_l3,R,A);
                cout << ans << "\n"; 
            }
        }else{
            //cout << "bb";
            //cout  << 180 * C / PI << "\n";
            double _l3 = l1 * sin(B);
            double _R = B - (PI / 2);
            

            if(ge(2 * A,_R)){
                double s = l1 *_l3 * sin(_R) - _l3 * _l3 * _R;
                ans += s;
                cout << ans << "\n";
            }else {
                double _C = PI - (PI - B) - 2 * A;
                double __l3 = l1 * sin(B) / sin(_C);
                ans += calc(l1,_l3,__l3,_R,A);
                cout << ans << "\n"; 
            }
        }
        
    }
}
int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int T;
    cin >> T;
    while(T --){
        solve();
    }
    return 0;
}