1. #include <bits/stdc++.h>
2. using namespace std;
3.  
4. int main()
5. {
6.  
7. int t;
8. cin>>t;
9. int cse=0;
10. while(t--){
11.      cse++;
12.     double a, b, c,sidea=0,sideb=0,sidec=0,areatriangle=0,areacircle=0,sum=0,s=0,anglea=0,angleb=0,anglec=0,sectora=0,sectorb=0,sectorc=0;
13.     cin >> a >> b >> c;
14.     sidea = a + b;
15.     sideb = a + c;
16.     sidec = b + c;
17.     s = (sidea + sideb + sidec) / 2;
18.     areatriangle = sqrt(s * (s - sidea) * (s - sideb) * (s - sidec));
19.     // cout << s << " s " << areatriangle << " areatriangle" << endl;
20.     anglea = (((sideb * sideb + sidec * sidec) - sidea * sidea) / (2 * sideb * sidec));
21.     // cout << "anglea " << anglea << endl;
22.     angleb = (((sidea * sidea + sidec * sidec) - sideb * sideb) / (2 * sidea * sidec));
23.     // cout << "angleb " << angleb << endl;
24.     anglec = (((sideb * sideb + sidea * sidea) - sidec * sidec) / (2 * sideb * sidea));
25.     // cout << "anglec " << anglec << endl;
26.     sectora = ((a*a)*(acos(anglea))*0.5);
27.     sectorb = ((b*b)*(acos(angleb))*0.5);
28.     sectorc = ((c*c)*(acos(anglec))*0.5);
29.     sum = areatriangle - (sectora + sectorb + sectorc);
30.     cout<<"Case "<<cse<<": "<<fixed<<setprecision(10)<<sum<<endl;
31.    
32. }
33.     return 0;
34. }