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


int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
  //  freopen("input.txt","r",stdin);//redirects standard input
 //freopen("output.txt","w",stdout);//redirects standard output

    int t;
    cin>>t;
    while(t--){
        int n;
        cin>>n;
        int x[n],y[n];
        for(int i=0;i<n;i++){
        	cin>>x[i];
        	cin>>y[i];
		}
		int minx=10000,maxx=-10000,miny=10000,maxy=-10000;
		int minxy,minyx,maxxy,maxyx;
		int minxi,minyi,maxxi,maxyi;
		for(int i=0;i<n;i++){
			if(x[i]<minx){
				minx=x[i];
				minxi = i;
				minxy=y[i];
			}
			if(x[i]>maxx){
				maxx=x[i];
				maxxi = i;
				maxxy=y[i];
			}
			if(y[i]<miny){
				miny=y[i];
				minyi = i;
				minyx=x[i];
			}
			if(y[i]>maxy){
				maxy=y[i];
				maxyi = i;
				maxyx=x[i];
			}
		}
		int a=0,b=0,c=0,d=0;
		for(int i=0;i<n;i++){
			if(x[i]==minx&&y[i]!=minxy){
				a++;
			}
			if(x[i]!=maxyx&&y[i]==maxy){
				b++;
			}
			if(x[i]==maxx&&y[i]!=maxxy){
				c++;
			}
			if(x[i]!=minyx&&y[i]==miny){
				d++;
			}
		}
		
		if(a||b||c||d){
			//cout<<"simple";
			//simple
			int flag=0;
			for(int i=0;i<n;i++){
				if((x[i]==minx||x[i]==maxx)&&(y[i]==maxy||y[i]==miny)){
					continue;	
				}else{
					flag=1;
					break;
				}
			}
			if(flag==1){
				//no
				cout<<"NO";
			}else{
				//yes
					cout<<"YES";
			}
		}else{
			float s1 = (maxy-minxy) / (maxyx-minx);
			float s2 = (maxy-maxxy) / (maxyx-maxx);
			float s3 = (maxxy-miny) / (maxx-minyx);
			float s4 = (minxy-miny) / (minx-minyx);
	
	
	
			for(int i=0;i<n;i++){
				float dx1 = x[i] - minx;
				float dy1 = y[i] - minxy;
				
				float dx2 = x[i] - maxx;
				float dy2 = y[i] - maxxy;
				
				if(dx1==0||dx2==0||dy1==0||dy2==0){
					//no
						cout<<"NO";
				}else{
					float m1 = dy1/dx1;
					float m2 = dy2/dx2;
					
					if((m1==s1||m1==s4)||(m2==s2||m2==s3)){
						//yes
						cout<<"YES";
					}else{
						//no
							cout<<"NO";
					}
					
				}
			}
		}
		if(t){
			cout<<endl;
		}
    }
    return 0;
}