Think Different

#include <iostream>
#include <cmath>
#include <cstdio>

using namespace std;

int main()
{
    int i, t;
    double   a, // area of ADMN
            BD,
            AP,
            AB,
            BC,
            ang_ABC;
    cin >> t;
    i = 1;
    while(i <= t){
        cin >> BD >> a;
        a = sqrt(a); //length of each side of ADMN
        ang_ABC = atan(a/BD);
        AB = BD/cos(ang_ABC);
        BC = AB/cos(ang_ABC);

        AP = BC/2; //length of AP=BP=CP
        printf("Case %d: %lf\n", i++, AP);
    }
    return 0;
}