/*input
2
3
0 0
0 1
1 0
4
0 0
0 2
2 0
1 1
*/
//__author__= "Rushal Verma"
#include<bits/stdc++.h>
using namespace std;
/*******useful typedef's *********/
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vi> vii;
typedef pair<int,int> pii;
typedef list<int>li;
typedef list<li>lii;
typedef set<int>si;
typedef set<ll> sl;
typedef set<si>sii;
typedef map<int,int> mi;
typedef map<ll, ll> mll;
/**************some useful macros/preprocessor********/
#define be_fast std::ios::sync_with_stdio(false);std::cin.tie(NULL); std::cout.tie(NULL);
#define print cout <<
#define ict int t;cin>>t;while(t--)
#define loop(a,b,c)   for (int (a)=(b); (a)<(c); ++(a))
#define loopn(a,b,c)  for (int (a)=(b); (a)<=(c); ++(a))
#define loopd(a,b,c)  for (int (a)=(b); (a)>=(c); --(a))
#define MOD 1000000007
#define INF 0x3f3f3f3f
#define limit 100000+5
#define pb push_back
#define mp make_pair
#define X first
#define Y second
///iterator range
#define all(c) c.begin(), c.end()
///reverse all iterator
#define rall(c) c.rbegin(),c.rend()
#define tr(c,i) for(typeof((c).begin() i = (c).begin(); i != (c).end(); i++))
#define present(c,x) ((c).find(x) != (c).end())
#define cpresent(c,x) (find(all(c),x) != (c).end())
/***************all user defines functions ******************/
/******************main starts here *************************/
int main()
{   be_fast;
	// freopen("source.in", "rt", stdin);
	// freopen("output.out", "wt", stdout);
	ict{
		int n;
		cin>>n;
		int x[n], y[n], flag =0;
		loop(i, 0, n){
			cin>>x[i]>>y[i];
		}
		if(n<3){
			flag =0;
		}
		else{
			ll prev_m1, prev_m2;
			if(x[0] != x[1]){
				prev_m1 =(y[1]-y[0])/(x[1]-x[0]);
			}
			else{
				prev_m1 =INF;
			}
			if(x[2] != x[1]){
				prev_m2 =(y[2]-y[1])/(x[2]-x[1]);
			}
			else{
				prev_m2 =INF;
			}
			if((prev_m1*prev_m2 == INF) || (prev_m1*prev_m2 == -INF) || (prev_m1 == prev_m2) || (prev_m1*prev_m2 == -1)){
				flag =0;
			}
			else
				flag =1;
			for(ll i =2;i<n-1;i+=1){
				ll curr_m1 =INF, curr_m2 =INF;
				if(x[i] != x[i-1]){
					curr_m1 =(y[i] - y[i-1])/(x[i]-x[i-1]);
				}
				else
					curr_m1 =INF;
				if(x[i+1] != x[i])
					curr_m2 =(y[i+1] - y[i])/(x[i+1] - x[i]);
				else
					curr_m2 =INF;
				if(prev_m1 != curr_m1 || prev_m2 != curr_m2 || prev_m1 != curr_m2 || prev_m2 != curr_m1){
					flag =1;
					cout<<"NO\n";
					break;
				}
				if((curr_m1*curr_m2 == INF) || (curr_m1*curr_m2 == -INF) || (curr_m1 == curr_m2) || (curr_m1*curr_m2 == -1)){
					flag =0;
				}
				else{
					flag =1;
					cout<<"NO\n";
					break;
				}
				cout<<curr_m1<<" "<<curr_m2<<endl;
			}
		}
		if(flag == 0){
			cout<<"YES\n";
		}
		// else{
		// 	cout<<"NooooO\n";
		// }
	}
return 0;
}
/*******************main ends here **************************/