#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;
#define drep(i, cc, n) for (ll i = (cc); i <= (n); ++i)
#define rep(i, n) drep(i, 0, n - 1)
#define all(a) (a).begin(), (a).end()
#define pb push_back
#define fi first
#define se second

const ll MOD = 1000000007;
const ll MOD2 = 998244353;
const ll INF = 1LL << 60;
const ll N_MAX = 2e5;

double solve(){
    double t, u, l;
    cin >> t >> u >> l;
    
    double second = sqrt(100*u*u*t*t+20*u*l) - 10*u*t;
    return second*3.6;
}

int main(){
    ll n;
    cin >> n;

    vector<double> ans(n);
    rep(i, n) ans[i] = solve();
    rep(i, n) cout << fixed << setprecision(2) << floor(100*ans[i])/100 << endl;
}