BNUOJ 52505 Euclidean Geometry

#include<bits/stdc++.h>
using namespace std;
int T;
double a[5];
double pi = acos(-1.0);
bool cmp(double x,double y)
{
    return x>y;
}
int main()
{
    scanf("%d",&T);
    while(T--)
    {
        scanf("%lf",&a[0]);
        scanf("%lf",&a[1]);
        scanf("%lf",&a[2]);
        sort(a,a+3);
        double r1 = 0;
        double r2 = a[1];
        double r3 = a[2] - a[1];
        double ans = pi * (r1*r1+r2*r2+r3*r3);
        printf("%.10f\n",ans);
    }
    return 0;
}