// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
#include<bits/stdc++.h>
using namespace std;

using ll = long long;
using ull = unsigned long long;
template <class T>
using pq = priority_queue<T>;
template <class T>
using qp = priority_queue<T, vector<T>, greater<T>>;
#define vec(T, A, ...) vector<T> A(__VA_ARGS__);
#define vvec(T, A, h, ...) vector<vector<T>> A(h, vector<T>(__VA_ARGS__));
#define vvvec(T, A, h1, h2, ...) vector<vector<vector<T>>> A(h1, vector<vector<T>>(h2, vector<T>(__VA_ARGS__)));

#define endl "\n"
#define spa ' '
#define len(A) A.size()
#define all(A) begin(A), end(A)

#define fori1(a) for(ll _ = 0; _ < (a); _++)
#define fori2(i, a) for(ll i = 0; i < (a); i++)
#define fori3(i, a, b) for(ll i = (a); i < (b); i++)
#define fori4(i, a, b, c) for(ll i = (a); ((c) > 0 || i > (b)) && ((c) < 0 || i < (b)); i += (c))
#define overload4(a, b, c, d, e, ...) e
#define fori(...) overload4(__VA_ARGS__, fori4, fori3, fori2, fori1)(__VA_ARGS__)

template <typename T>
vector<tuple<ll, T>> ENUMERATE(vector<T> &A, ll s = 0){
    vector<tuple<ll, T>> ret(A.size());
    for(int i = 0; i < A.size(); i++) ret[i] = {i + s, A[i]};
    return ret;
}

vector<tuple<ll, char>> ENUMERATE(string &A, ll s = 0){
    vector<tuple<ll, char>> ret(A.size());
    for(int i = 0; i < A.size(); i++) ret[i] = {i + s, A[i]};
    return ret;
}

#define enum1(A) fori(A.size())
#define enum2(a, A) for(auto a:A)
#define enum3(i, a, A) for(auto&& [i, a]: ENUMERATE(A))
#define enum4(i, a, A, s) for(auto&& [i, a]: ENUMERATE(A, s))
#define enum(...) overload4(__VA_ARGS__, enum4, enum3, enum2, enum1)(__VA_ARGS__)

template <typename T, typename S>
vector<tuple<T, S>> ZIP(vector<T> &A, vector<S> &B){
    int n = min(A.size(), B.size());
    vector<tuple<T, S>> ret(n);
    for(int i = 0; i < n; i++) ret[i] = {A[i], B[i]};
    return ret;
}

template <typename T, typename S>
vector<tuple<ll, T, S>> ENUMZIP(vector<T> &A, vector<S> &B, ll s = 0){
    int n = min(A.size(), B.size());
    vector<tuple<ll, T, S>> ret(n);
    for(int i = 0; i < n; i++) ret[i] = {i + s, A[i], B[i]};
    return ret;
}

#define zip4(a, b, A, B) for(auto&& [a, b]: ZIP(A, B))
#define enumzip5(i, a, b, A, B) for(auto&& [i, a, b]: ENUMZIP(A, B))
#define enumzip6(i, a, b, A, B, s) for(auto&& [i, a, b]: ENUMZIP(A, B, s))
#define overload6(a, b, c, d, e, f, g, ...) g
#define zip(...) overload6(__VA_ARGS__, enumzip6, enumzip5, zip4, _, _, _)(__VA_ARGS__)

vector<char> stoc(string &S){
    int n = S.size();
    vector<char> ret(n);
    for(int i = 0; i < n; i++) ret[i] = S[i];
    return ret;
}

#define INT(...) int __VA_ARGS__; inp(__VA_ARGS__);
#define LL(...) ll __VA_ARGS__; inp(__VA_ARGS__);
#define STRING(...) string __VA_ARGS__; inp(__VA_ARGS__);
#define CHAR(...) char __VA_ARGS__; inp(__VA_ARGS__);
#define VEC(T, A, n) vector<T> A(n); inp(A);
#define VVEC(T, A, n, m) vector<vector<T>> A(n, vector<T>(m)); inp(A);

const ll MOD1 = 1000000007;
const ll MOD9 = 998244353;

template<class T> auto min(const T& a){
    return *min_element(all(a));
}
template<class T> auto max(const T& a){
    return *max_element(all(a));
}
template <class T, class S>
inline bool chmax(T &a, const S &b) {
  return (a < b ? a = b, 1 : 0);
}
template <class T, class S>
inline bool chmin(T &a, const S &b) {
  return (a > b ? a = b, 1 : 0);
}

void FLUSH(){cout << flush;}
void print(){cout << endl;}
template <class Head, class... Tail>
void print(Head &&head, Tail &&... tail) {
    cout << head;
    if (sizeof...(Tail)) cout << spa;
    print(forward<Tail>(tail)...);
}
template<typename T>
void print(vector<T> &A){
    int n = A.size();
    for(int i = 0; i < n; i++){
        cout << A[i];
        if(i == n - 1) cout << endl;
        else cout << spa;
    }
}
template<typename T>
void print(vector<vector<T>> &A){
    for(auto &row: A) print(row);
}
template<typename T, typename S>
void print(pair<T, S> &A){
    cout << A.first << spa << A.second << endl;
}
template<typename T, typename S>
void print(vector<pair<T, S>> &A){
    for(auto &row: A) print(row);
}
template<typename T, typename S>
void prisep(vector<T> &A, S sep){
    int n = A.size();
    for(int i = 0; i < n; i++){
        cout << A[i];
        if(i == n - 1) cout << endl;
        else cout << sep;
    }
}
template<typename T, typename S>
void priend(T A, S end){
    cout << A << end;
}
template<typename T>
void priend(T A){
    priend(A, spa);
}
template<class... T>
void inp(T&... a){
    (cin >> ... >> a);
}
template<typename T>
void inp(vector<T> &A){
    for(auto &a:A) cin >> a;
}
template<typename T>
void inp(vector<vector<T>> &A){
    for(auto &row:A) inp(row);
}
template<typename T, typename S>
void inp(pair<T, S> &A){
    inp(A.first, A.second);
}
template<typename T, typename S>
void inp(vector<pair<T, S>> &A){
    for(auto &row: A) inp(row.first, row.second);
}

template<typename T>
T sum(vector<T> &A){
    T tot = 0;
    for(auto a:A) tot += a;
    return tot;
}

template<typename T>
pair<vector<T>, map<T, int>> compression(vector<T> X){
    sort(all(X));
    X.erase(unique(all(X)), X.end());
    map<T, int> mp;
    for(int i = 0; i < X.size(); i++) mp[X[i]] = i;
    return {X, mp};
}

using ld = long double;
const ld PI = acos(-1);

complex<ld> intersection(complex<ld> &p1, complex<ld> &p2, complex<ld> &p3, complex<ld> &p4){
    ld det = (p1.real() - p2.real()) * (p4.imag() - p3.imag()) - (p4.real() - p3.real()) * (p1.imag() - p2.imag());
    ld t = ((p4.imag() - p3.imag()) * (p4.real() - p2.real()) + (p3.real() - p4.real()) * (p4.imag() - p2.imag())) / det;
    ld x = t * p1.real() + (1.0 - t) * p2.real();
    ld y = t * p1.imag() + (1.0 - t) * p2.imag();
    return complex<ld>{x, y};
}

void solve(){
    INT(L1, L2, alpha, beta);
    ld l1 = L1;
    ld l2 = L2;
    ld alrad = ld(alpha * PI / 180.0);
    ld berad = ld(beta * PI / 180.0);
    ld ans = 0;
    ld l = l1 + l2;
    ans += l * l * alrad;
    ans += l2 * l2 * berad;
    if((beta <= 90) || (beta == 180)){
        print(ans);
        return;
    }
    complex<ld> O, pr, pl, qr, ql;
    O = {0, 0};
    pr = l1 * complex<ld>{cos(PI / 2 - alrad), sin(PI / 2 - alrad)};
    pl = l1 * complex<ld>{cos(PI / 2 + alrad), sin(PI / 2 + alrad)};
    qr = pr + l2 * complex<ld>{cos(PI / 2 - alrad - berad), sin(PI / 2 - alrad - berad)};
    ql = pl + l2 * complex<ld>{cos(PI / 2 + alrad - berad), sin(PI / 2 + alrad - berad)};

    auto projection=[](complex<ld> &a, complex<ld> &b, complex<ld> &p){
        auto d1 = p - a;
        auto d2 = a - b;
        ld t = (d1.real() * d2.real() + d1.imag() * d2.imag()) / norm(a - b);
        return a + (a - b) * t;
    };

    auto pqro = projection(pr, qr, O);
    if(pqro.imag() > qr.imag()) qr = pqro;

    ld theta = atan2(qr.imag(), qr.real());
    ld dtheta = PI / 2 - alrad - theta;
    ld darea = 0;
    ld r = abs(qr);
    darea += abs(pr.imag() * qr.real() - pr.real() * qr.imag()) / 2.0;
    if(dtheta <= 2 * alrad){
        darea -= r * r * dtheta / 2.0;
    }
    else{
        darea -= r * r * 2.0 * alrad / 2.0;
        auto pq = qr * complex<ld>{cos(alrad * 2), sin(alrad * 2)};
        complex<ld> ppp = {cos(PI / 2.0 - alrad * 3.0), sin(PI / 2.0 - alrad * 3.0)};
        auto pp = intersection(O, ppp, pr, qr);
        pr /= abs(pr);
        pr *= abs(pp);

        darea -= abs(pr.imag() * pq.real() - pr.real() * pq.imag()) / 2.0;
    }
    // print(ans, darea);
    ans += 2 * darea;
    print(ans);

}

int main(){
    cin.tie(0)->sync_with_stdio(0);
    cout << fixed << setprecision(12);
    int t;
    t = 1;
    cin >> t;
    while(t--) solve();
    return 0;
}