uva 10991

#include <iostream>
#include<math.h>
#include<stdio.h>
using namespace std;

int main()
{

    double r1,r2,r3,a,b,c,A,B,C,s,area;
    int t;
    scanf("%d",&t);
    while(t--){
        scanf("%lf%lf%lf",&r1,&r2,&r3);
        a=r1+r2;
        b=r2+r3;
        c=r3+r1;
        s =(a+b+c)/2;
        C = acos((a*a+b*b-c*c)/(2*a*b));
        A = acos((b*b+c*c-a*a)/(2*b*c));
        B = acos((c*c+a*a-b*b)/(2*c*a));
        area =sqrt(s*(s-a)*(s-b)*(s-c))-(r1*r1*B+r2*r2*C+r3*r3*A)/2;
        printf("%.6lf\n",area);
    }
    return 0;
}