#include <iostream>
#include <stdio.h>
#include <cmath>
#include <cstring>
#include <vector>
#include <algorithm>
#include <set>
#include <stack>
#include <map>
#include <iomanip>
#include <string>
#define INPUT  "input.txt"
#define OUTPUT "output.txt"
using namespace std;

int t;
const double pi = atan(1.0) * 4.0;
double r[3];

int main()
{
    cin >> t;
    while (t--)
    {
        cin >> r[0] >> r[1] >> r[2];
        double R = (r[0] * r[1] * r[2]) / (r[0] * r[1] + r[1] * r[2] + r[0] * r[2] + 2.0 * sqrt(r[0] * r[1] * r[2] * (r[0] + r[1] + r[2])));
        cout << fixed << setprecision(9) << R << '\n'; 
    }
    return 0;
}
//(c)gacongnghiep