import java.io.*;
import java.util.*;

public class Solution {

    public static void main(String[] args) {
        Scanner sc= new Scanner(System.in);
        int q = sc.nextInt();
        for(int w = 0 ;w<q;w++)
            {
            int n= sc.nextInt();
            int arr[][]=new int[n][2];
            int flag = 0;
            for(int i=0;i<n;i++)
                {
                arr[i][0]=sc.nextInt();
                arr[i][1]=sc.nextInt();
            }
            
            int c=0;
            double c1 =0;
            double c2 = 0;
            int pointer=0;
            for(int i = 1 ;i<n;i++)
                {
                if(arr[i][0]-arr[i-1][0]==0)
                   continue;
                 else if(c==0)
                    {
                    c++;
                    c2=(arr[i][1]+arr[i-1][1])*1.0/2.0;
                    c1=(arr[i][0]+arr[i-1][0])*1.0/2.0;
                    continue;
                }
                else if(c2!=(arr[i][1]+arr[i-1][1])*1.0/2.0||c1!=(arr[i][0]+arr[i-1][0])*1.0/2.0)
                    ++pointer;
                 if(pointer==1)
                    break;
            }
            if(pointer==1)
                System.out.println("NO");
            else
                System.out.println("YES");
        }
    }
}