#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define M_PI acos(-1)

using namespace std;

int main()
{
    ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
	cout.tie(nullptr);
	cout << fixed << setprecision(12);

	int t = 1;
	cin >> t;
    while(t-->0)
    {
        double l1, l2, t1, t2;
        cin >> l1 >> l2 >> t1 >> t2;

        if(t2 <= 90) cout << t1 / 180 * M_PI * pow(l1 + l2, 2) + t2 / 180 * M_PI * pow(l2, 2) << "\n";
        else
        {
            double area = t1 / 180 * M_PI * pow(l1 + l2, 2) + t2 / 180 * M_PI * pow(l2, 2);
            double t3 = atan2(l2 * sin(t2), l1 - l2 * cos(t2));

            area += l1 * l2 * sin(t2);
            area -= t3 * (pow(l1 - l2 * cos(t2), 2) + pow(l2 * sin(t2), 2));

            cout << area << "\n";
        }
    }
}