#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
       long int x[10],y[10],i,n,no,j,dist1,dist2,dist,flag;
    cin>>no;
    while(no--)
        {
        cin>>n;
        for(i=1;i<=n;i++)
            cin>>x[i]>>y[i];
        flag=0;
        dist1=sqrt((x[0]-x[1])*(x[0]-x[1])+(y[0]-y[1])*(y[0]-y[1]));
        dist2=sqrt((x[2]-x[1])*(x[2]-x[1])+(y[2]-y[1])*(y[2]-y[1]));
        for(i=1;i<=n;i++)
            {
            for(j=i+1;j<=n;j++)
              {
                dist=sqrt((x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j]));
                if(dist!=dist1&&dist!=dist2)
                    {
                    flag=1;
                    break;
                }
            }
            if(flag)
                break;
        }
        if(flag)
            cout<<"NO\n";
        else
            cout<<"YES\n";
    }
    return 0;
}