#include<bits/stdc++.h>
using namespace std;
#define double long double
#define int long long
const double pi = acos(-1);
void solve(){
	double a, b, r, c;
	cin >> a >> b >> r;
	c = sqrt(a * a + b * b);
	double d; cin >> d;
	d = d * pi / 180.0;
	// double h = sin(d) * r;
	// double ans = sqrt(c * c - h * h) + r * cos(d);
	double tha = atan(b/ (a + r));
	double x = (a + r) * tan(d);
	// cout << d << " " << tha << endl;
	if(d <= tha) cout << fixed << setprecision(9)<< (double)(x / sin(d) + (b - x) * sin(d)  - r) << endl;
	else cout <<fixed << setprecision(9)<< (double) (sqrt((a + r) * (a + r) + b * b) - r) << endl;
	}
signed main(){
	int T;
	cin >> T;
	while(T--){
		solve();
	}
}