#include <iostream>

 #include<cstdio>

 #include<cmath>

 #include<cstring>

 using namespace std;

 #define eps 1e-8

 const double PI=acos(-1.0);

 double l,d,s;

 double solve(){

     if(s-d<eps)//1

         return PI*s*s;

     double dist=sqrt(0.25*l*l+d*d),ans=;

     if(s-dist<eps){//

         double angle=acos(d/s);

         ans=(PI-angle)*s*s+s*d*sin(angle);

     }else{//3,4

         double angle=asin(0.5*l/dist);

         ans+=(PI-angle)*s*s+0.5*l*d;

         s-=dist;

         angle+=0.5*PI;

         ans+=angle*s*s;

         if(s+s-l>eps){

             double angle1=acos(0.5*l/s);

             ans-=angle1*s*s-0.5*sin(angle1)*s*l;

         }

     }

     return ans;

 }

 int main(int argc, char** argv) {

     int t;

     double ans;

     scanf("%d",&t);

     while(t--){

         scanf("%lf%lf%lf",&l,&d,&s);

         ans=solve();

         printf("%.2lf\n",ans);

     }

     return ;

 }