#include <bits/stdc++.h>

using namespace std;

int t, d, x, y, i, xx, yy, a, b;

int main() {
    cin >> t;
    while (t--) {
        i = 1;
        cin >> d >> x >> y;
        a = x * x + y * y;
        xx = x;
        yy = y;
        while (xx - i * y >= 0 && yy + i * x <= d) i++;
        i--;
        b = (x - (xx - i * y)) * (x - (xx - i * y));
        b += (yy + i * x - y) * (yy + i * x - y);
        cout << sqrt(a*b) << '\n';

    }
}