#include <bits/stdc++.h>

using namespace std;

#define forn(i,n) for(int i=0;i<n;++i)
#define rforn(i,n) for(int i=n-1;i>=0;--i)
#define out(a) {cout<<a;return 0;}

#define sqr(a) ((a)*(a))
#define max(a,b) ((a>b)?(a):(b))
#define min(a,b) ((a<b)?(a):(b))

#define maxn 400009

#define mp make_pair
#define f first
#define s second
int m,n;

vector<int> x;
vector<int> y;


int check(int x1,int y1,int x2,int y2){
 //   cout<<x1<<' '<<y1<<' '<<x2<<' '<<y2<<'\n';
    if(x1 == x2 || y1 == y2)
        return 0;

    for(int i=0;i<n;++i)
        if(x[i]!=x1 && x[i]!=x2 && y[i]!=y1 && y[i]!=y2)
            return 0;


    return 1;
}

int solve(){

    cin>>n;
    int a,b;
    x.clear();
    y.clear();
    int x1 = 1000000,x2= -100000,y1= 1000000,y2= -100000;
    for(int i=0;i<n;++i)
    {
        cin>>a>>b;
        x1 = min(x1,a);
        x2 = max(x2,a);
        y1 = min(y1,b);
        y2 = max(y2,b);
        x.push_back(a);
        y.push_back(b);
    }

    int t = 0;


    t+=check(x1,y1,x2,y1+x2-x1);
    t+=check(x1,y1,x1+y2-y1,y2);
    t+=check(x2 - (y2-y1) ,y1,x2,y2);
    t+=check(x1,y2-(x2-x1),x2,y2);

    if(x1==x2 || y1 == y2)
        ++t;

    t+=check(x1,y1,x2,y2);

    if(t)
        cout<<"YES\n";
    else
        cout<<"NO\n";

    return 0;

}

int main(){

    int test;
    cin>>test;

    while(test--){
        solve();
    }

}