text: #include <cstdio>
  #include <iostream>
  #include <cmath>
  
  using namespace std;
  
  int main()
  {
      int test_case;
  
      scanf("%d", &test_case);
  
      double R1 , R2 , R3;
      double a , b , c , s , area_of_triangle , areaR1 , areaR2 , areaR3 , result;
      double A , B , C;
  
      for(int i = 0 ; i < test_case ; i++)
      {
          scanf("%lf %lf %lf" , &R1 , &R2 ,&R3);
  
          a = R1 + R2;
          b = R2 + R3;
          c = R3 + R1;
  
          s = (a+b+c)/2 ;
  
          area_of_triangle = sqrt(s * (s-a) * (s-b) * (s-c));
  
          A = acos((b*b+c*c-a*a)/(2*b*c));
          B = acos((c*c+a*a-b*b)/(2*a*c));
          C = acos((a*a+b*b-c*c)/(2*a*b));
  
          areaR1 = R1 * R1 * B ;
          areaR2 = R2 * R2 * C ;
          areaR3 = R3 * R3 * A ;
  
          result = area_of_triangle - 0.5 * (areaR1 + areaR2 + areaR3)  ;
  
          printf("Case %d: %.10lf\n", i+1 , result);
  
      }
      return 0;
  }
  