#include <bits/stdc++.h> 
using namespace std;
using ll =long long;
#define all(v) v.begin(),v.end()
 #define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)

void solve() {
string T,U,L;cin>>T>>U>>L;
string k="";
for(auto x:T) {
  if(x=='.') continue;
  k+=x;
}
ll t=stoll(k);

k="";
for(auto x:U) {
  if(x=='.') continue;
  k+=x;
}
ll u=stoll(k);

k="";
for(auto x:L) {
  if(x=='.') continue;
  k+=x;
}
ll l=stoll(k);


ll ans=-1*u*t*36;
 ll b=sqrt(u*u*t*t+2000*u*l)*36;
 



if(abs(ans)>=b) {
  cout<<"0.00"<<endl;
  return ;
}
ans+=b;


string a=to_string(ans);

if(a.size()<3) {
  cout<<"0.00"<<endl;
}
else if(a.size()==3) {
  cout<<"0.0"<<a[0]<<endl;
}
else if(a.size()==4) {
  cout<<"0."<<a[0]<<a[1]<<endl;
}
else {
  for(ll i=0;i<a.size()-4;i++) {
    cout<<a[i];
  }
  cout<<'.';
  for(ll i=a.size()-4;i<a.size()-2;i++) {
    cout<<a[i];
  }
cout<<endl;
}

}

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
    ll t;cin>>t;
    for(ll i=0;i<t;i++) {
        solve();
    }
}