#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
int sqr(int x){
    return x*x;
}
bool isRectangle(int x1, int y1,
                 int x2, int y2,
                 int x3, int y3,
                 int x4, int y4)
{
  int cx,cy;
  int dd1,dd2,dd3,dd4;

  cx=(x1+x2+x3+x4)/4;
  cy=(y1+y2+y3+y4)/4;

  dd1=sqr(cx-x1)+sqr(cy-y1);
  dd2=sqr(cx-x2)+sqr(cy-y2);
  dd3=sqr(cx-x3)+sqr(cy-y3);
  dd4=sqr(cx-x4)+sqr(cy-y4);
  return dd1==dd2 && dd1==dd3 && dd1==dd4;
}
int main() {
    int q;
    int n;
    cin >> q;
    while(q--){
        cin >> n;
        pair <int,int> A[n];
        for(int i=0;i<n;i++){
            cin >> A[i].first >> A[i].second;
        }
        int flag=0;
        switch(n){
            case 1:
                flag=1;
                break;
            case 2:
                if(A[0].first==A[1].first || A[0].second==A[1].second)
                    flag=1;
                break;
            case 3:
                if(A[0].first==A[1].first && (A[0].second==A[2].second || A[1].second==A[2].second))
                    flag=1;
                else if(A[1].first==A[2].first && (A[1].second==A[0].second || A[2].second==A[0].second))
                    flag=1;
                break;
            case 4:
                if(isRectangle(A[0].first,A[0].second,A[1].first,A[1].second,A[2].first,A[2].second,A[3].first,A[3].second)){
                    flag=1;
                    break;
                }
            default:
                break;
        }
        if(flag==0){
            cout << "NO" << endl;
        }
        else{
            cout << "YES" << endl;
        }
    }
    return 0;
}