#include <bits/stdc++.h>
#ifdef SHARAELONG
#include "../../cpp-header/debug.hpp"
#endif
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef long double ld;

const ld PI = 3.14159265358979323846264;
const ld eps = 1e-10;

void solve() {
    ld l1, l2, a, b;
    cin >> l1 >> l2 >> a >> b;
    a *= PI / 180;
    b *= PI / 180;
    
    ld ans = (l1+l2)*(l1+l2)*a + l2*l2*b;
    if (b <= PI/2 + eps) {
        cout << ans << '\n';
        return;
    }

    ld thres = acos(l2/l1);
    if (b < PI - thres - eps) {
        if (2*a < b-PI/2 - eps) {
            ld h = l1 * sin(PI-b);
            ans += l1*l1*cos(PI-b)*sin(PI-b);
            ans -= 2*h*h*a;
            ans -= h*h / tan(PI+2*a-b);
        } else {
            ld h = l1 * sin(PI-b);
            ans += l1*l1*cos(PI-b)*sin(PI-b);
            ans -= h*h*(b-PI/2);
        }
    } else {
        ld l = l1*l1 + l2*l2 - 2*l1*l2*cos(PI-b);
        l = sqrt(l);
        ans += l1*l2*sin(PI-b);
        if (l < eps) {
            cout << ans << '\n';
            return;
        }
        ld g = acos((l1-l2*cos(PI-b)) / l);
        if (2*a < g-eps) {
            ans -= l*l1*sin(g-2*a);
            ans -= 2*l*l*a;
        } else {
            ans -= l*l*g;
        }
    }
    cout << ans << '\n';
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    cout << fixed << setprecision(15);
    
    int cases;
    cin >> cases;
    while (cases--) solve();
}