import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;

public class Solution {

    public static void main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
        Scanner scan = new Scanner(System.in);
        int q = scan.nextInt();
        for (int query = 0; query < q; query++) {
            int n = scan.nextInt();
            int x[] = new int[n];
            int y[] = new int[n];
            for (int i = 0; i < n; i++) {
                x[i] = scan.nextInt();
                y[i] = scan.nextInt();
            }
            // 
            boolean output = true;
            HashMap<Double,Integer> map = new HashMap();
            for (int i = 0; i < n; i++) {
                for (int j = i+1; j < n; j++) {
                    double lengthx = Math.abs(x[j]-x[i]) * Math.abs(x[j]-x[i]);
                    double lengthy = Math.abs(y[j]-y[i]) * Math.abs(y[j]-y[i]);
                    double length = Math.sqrt(lengthx + lengthy);
                    if (length == 0) {
                        output = false;
                        break;
                    }
                    if (map.containsKey(length)) {
                        int val = map.get(length);
                        if (val == 2) {
                            output = false;
                            break;
                        }
                        else {
                            map.put(length,val+1);
                        }
                    }
                    else {
                        map.put(length,1);
                    }
                }
                if (!output) break;
            } 
            System.out.println(output ? "YES" : "NO");
        }
    }
}