#include<bits/stdc++.h>
using namespace std;
 
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define LC k<<1
#define RC k<<1|1
#define IO cin.sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define all(x) (x).begin(), (x).end()
#define SZ(x) ((int)(x).size())
#define rep(i,a,n) for (int i = a; i < n; i++)
#define repn(i,a,n) for (int i = a; i <= n; i++)
#define per(i,a,n) for (int i = n - 1; i >= a; i--)
#define pern(i,a,n) for (int i = n; i >= a; i--)
 
typedef long long LL;
typedef unsigned long long ull;
typedef pair<int, int> PII;
typedef pair<double, double> PDD;
typedef long double LD;
 
const int N = 210;
const int M = 1100000;
const int mod = 998244353;
const int inf = (int)1e9;
const long long INF = (long long)1e18;
const double eps = 1e-15, pi = acos(-1.0);

#define double LD
inline int dcmp(double x) {
    return (x > eps) - (x < -eps);
}

double x, y, a, b;

double hs (double a, double b, double c) {
	double p = (a + b + c) / 2;
	return sqrt(p * (p - a) * (p - b) * (p - c));
}
double cs (double r, double th) {
	return th * r * r / 2;
}
double cosa (double x, double y, double z) {
	return acos((x * x + y * y - z * z) / (2 * x * y));
}

void solve() {
	cin >> y >> x >> a >> b;
	a = a * pi / 180; b = b * pi / 180;
	double z = sqrt(x * x + y * y - 2 * x * y * cos(pi - b));
	double s = hs(x, y, z);
	double h = 2 * s / x, res;
	if (dcmp(b - pi / 2) <= 0) res = 0;
	else {
		double x1, r, th, th2;
		if (dcmp(x * x + z * z - y * y) >= 0) {
			r = h; x1 = y * cos(pi - b); 
			th = b - pi / 2; th2 = pi / 2;
		}
		else {
			r = z; x1 = x; 
			th = cosa(z, y, x); th2 = cosa(x, z, y);
		}
		if (dcmp(th - 2 * a) > 0) {
			double t1 = th - 2 * a, t2 = th2, t3 = pi - t1 - t2;
			double l3 = r, l2 = l3 * sin(t2) / sin(t3), l1 = l3 * sin(t1) / sin(t3);
			res = hs(x1, r, y) - cs(r, 2 * a) - hs(l1, l2, l3);
		}
		else {
			res = hs(x1, r, y) - cs(r, th);
		}
	}
	double ans = 2 * (cs(x + y, a) + cs(x, b) + res);
	cout << fixed << setprecision(10) << ans << "\n"; 
}

int main() {
	int T;
	cin >> T;
	repn(i, 1, T) solve(); 
	return 0;
}