#include<bits/stdc++.h>

using namespace std;

#define int long long

using db = long double;

const db pi = acosl(-1.0L);

void solve(){
	int l, r, a, b;
	cin >> l >> r >> a >> b;

	db x = pi * a / 180;
	db y = pi * b / 180;
	db ans = x * ((l + r) * (l + r)) + y * r * r;

	if(b > 90){
		if(sinl(y - pi / 2) * l <= r){
			ans += sinl(y - pi / 2) * l * cosl(y - pi / 2) * l;
			ans -= (y - pi / 2) * cosl(y - pi / 2) * l * cosl(y - pi / 2) * l;
			if(y - pi / 2 > x + x){
				db z = y - pi / 2 - x - x;
				db len = cosl(y - pi / 2) * l;
				ans -= tanl(z) * len * len;
				ans += z * len * len;
			}
		}else{
			ans += sinl(y) * l * r;
			db d = sinl(y) * r * sinl(y) * r + (l - r * cosl(pi - y)) * (l - r * cosl(pi - y));
			ans -= atanl((sinl(y) * r) / (l - r * cosl(pi - y))) * d;
		}
	}

	cout << ans << "\n";
	return;
}

signed main(){
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	cout << fixed << setprecision(20);

	int t; cin >> t;
	while(t--) solve();

	return 0;
}

/*
5
2 1 20 20
3 3 0 0
20 20 90 120
20 10 50 170
100 10 1 93
*/