#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<cstdio>
#include<string>
#include<iostream>
#include<cstring>
#include<cmath>
#include<stack>
#include<queue>
#include<vector>
#include<map>
#include<stdlib.h>
#include<algorithm>
#define LL __int64
#define FIN freopen("in.txt","r",stdin)
using namespace std;
const int MAXN=200+5;
const double INF=1e9;
const double eps=1e-2;
struct node
{
    double x, y;
} po[MAXN];
int n;

double dis(int a,int b)
{
    return sqrt( (po[a].x-po[b].x) * (po[a].x-po[b].x) + (po[a].y-po[b].y) * (po[a].y-po[b].y) );
}

double calc(int a,int b,int c)
{
    double lenA=dis(a,b);
    double lenB=dis(a,c);
    double lenC=dis(b,c);
    double p=(lenA+lenB+lenC)/2;
    return sqrt(p*(p-lenA)*(p-lenB)*(p-lenC));
}

int main()
{
    int kase;
    scanf("%d",&kase);
    while(kase--)
    {
        scanf("%d",&n);
        for(int i=0;i<n;i++) scanf("%lf %lf",&po[i].x,&po[i].y);
        double ans=INF;
        bool flag=false;
        for (int i=0;i<n;i++)
        {
            for (int j=i+1;j<n;j++)
            {
                for (int k=j+1;k<n;k++)
                {
                    double tmp=calc(i,j,k);
                    if(fabs(tmp)>=eps)
                    {
                        flag=true;
                        ans=min(ans,tmp);
                    }
                }
            }
        }
        if (!flag) printf("Impossible\n");
        else printf("%.2lf\n",ans);
    }
}