/*
        SUPTO
        UNIVERSITY OF DHAKA
*/
#include <bits/stdc++.h>
using namespace std;
#define D(x) cerr<<#x " = "<<(x)<<endl
#define pb push_back
#define ff first
#define ss second
#define mem(a) memset(a,0,sizeof(a))
#define _set(a) memset(a,-1,sizeof(a))
typedef long long int ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
#define eps 1e-9
#define MAX 20
#define MAXL 20
#define MAXE 100000
//const int mod = 100000007;
//int dx[] = {0,0,1,-1};
//int dy[] = {1,-1,0,0};
//int dx[] = {-1,-1,-1,0,0,1,1,1};
//int dy[] = {-1,0,1,-1,1,-1,0,1};
const int inf = 100000;
pii p[15];
bool check(pii p1, pii p2, pii p3)
{
    if((p3.ff-p1.ff)*(p1.ss-p2.ss) == (p1.ff-p2.ff)*(p3.ss-p1.ss)) return true;
    return false;
}
int main()
{
    //freopen("input.txt", "r", stdin);
    //freopen("output.txt", "w", stdout);
    //ios_base::sync_with_stdio(false);
    int q, n, i;
    scanf("%d", &q);
    while(q--)
    {
        int xmin = inf, xmax = -inf, ymin = inf, ymax = -inf;
        scanf("%d", &n);
        for(i = 0; i < n; i++)
        {
            scanf("%d %d", &p[i].ff, &p[i].ss);
            xmin = min(xmin, p[i].ff);
            xmax = max(xmax, p[i].ff);
            ymin = min(ymin, p[i].ss);
            ymax = max(ymax, p[i].ss);
        }
        if(xmin == xmax) xmax++;
        if(ymin == ymax) ymax++;
        for(i = 0; i < n; i++)
        {
            if(check(make_pair(xmin, ymin), make_pair(xmin, ymax), p[i])) continue;
            if(check(make_pair(xmin, ymax), make_pair(xmax, ymax), p[i])) continue;
            if(check(make_pair(xmax, ymax), make_pair(xmax, ymin), p[i])) continue;
            if(check(make_pair(xmax, ymin), make_pair(xmin, ymin), p[i])) continue;
            break;
        }
        if(i < n) printf("NO\n");
        else printf("YES\n");
    }
    return 0;
}