#include <iostream>
#include <vector>
#include <climits>

using namespace std;

bool p(int x1, int y1, int x2, int y2, int a, int b) {
	if(x1 > x2) {
		swap(x1, x2);
	}
	if(y1 > y2) {
		swap(y1, y2);
	}
	if(x1 <= a && a <= x2 && y1 <= b && b <= y2 && ((a - x1) * (y2 - y1) ==  (b - y1) * (x2 - x1))) {
		return true;
	}
	return false;
} 

int main() {
	int ite;
	cin >> ite;
	while(ite--) {
		int n; cin >> n;
		vector<pair<int, int> > v;
		int xmin = INT_MAX, xmax = INT_MIN, ymin = INT_MAX, ymax = INT_MIN; 
		for(int i=0; i<n; i++ ) {
			int a, b; cin >> a >> b; v.push_back(make_pair(a, b));
			xmin = min(xmin, a);
			xmax = max(xmax, a);
			ymin = min(ymin, b);
			ymax = max(ymax, b);
		}
		bool can = true;
		for(int i=0; i<n && can; i++ ) {
			can &= (p(xmax, ymin, xmin, ymin, v[i].first, v[i].second) ||
				p(xmin, ymin, xmin, ymax, v[i].first, v[i].second) ||
				p(xmin, ymax, xmax, ymax, v[i].first, v[i].second) ||
				p(xmax, ymax, xmax, ymin, v[i].first, v[i].second));
		}
		if(can) {
			cout << "YES" << endl;
		} else {
			cout << "NO" << endl;
		}
	}
}