#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
int returnEdgeMag(int ax,int ay,int bx,int by){
    int x= (bx-ax);
    int y= (by-ay);
    return( sqrt(x*x+y*y));
    
}

int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    int q,n;
    cin>>q>>n;
    int cords[n][2];
    for(int j=0;j<q;j++){
        for(int i=0;i<n;i++){
            cin>>cords[i][0]>>cords[i][1];
        }
        int preMag=0;
        int flag=0;
        for(int i=0;i<n;i++){
            //cout<<"edge "<<i<<endl;
            if(i==0){
                preMag=returnEdgeMag(cords[i][0],cords[i][1],cords[1][0],cords[1][1]);
            }
            if(i>0 && i!=n-1){
                if(preMag!=returnEdgeMag(cords[i][0],cords[i][1],cords[i+1][0],cords[i+1][1])){
                    cout<<"NO"<<endl;
                    flag=1;
                    break;
                }
            }else if(i==3){
                if(preMag!=returnEdgeMag(cords[i][0],cords[i][1],cords[0][0],cords[0][1])){
                    cout<<"NO"<<endl;
                    flag=1;
                    break;
                }
            }
        }
        if(flag==0){
            cout<<"YES"<<endl;
        }
        
        
        
    }
    return 0;
}