#include <iostream>
#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <queue>
#include <map>
#include <algorithm>
#include <set>
#define MM(a) memset(a,0,sizeof(a))
typedef long long ll;
typedef unsigned long long ULL;
const double eps = 1e-12;
const int inf = 0x3f3f3f3f;
const double pi=acos(-1);
using namespace std;

struct Point{
    int x,y;
    void read()
    {
        scanf("%d%d",&x,&y);
    }
}p[105],tubao[105];

int dcmp(double a)
{
    if(fabs(a)<eps) return 0;
    else if(a>0) return 1;
    else return -1;
}

Point operator-(Point a,Point b)
{
    return (Point){a.x-b.x,a.y-b.y};
}

double dis(Point a)
{
    return sqrt(a.x*a.x+a.y*a.y);
}

double cross(Point a,Point b)
{
    return  a.x*b.y-b.x*a.y;
}

double dot(Point a,Point b)
{
    return a.x*b.x+a.y*b.y;
}

bool cmp(Point a,Point b)
{
    if(a.x!=b.x) return a.x<b.x;
    else return a.y<b.y;
}

int  convex_hull(Point *p,int n,Point *tubao)
{
    sort(p+1,p+n+1,cmp);
    int m=0;
    for(int i=1;i<=n;i++)
    {
        while(m>=2&&cross(p[i]-tubao[m-1],tubao[m]-tubao[m-1])>0) m--;
        tubao[++m]=p[i];
    }
    int k=m;
    for(int i=n-1;i>=1;i--)
    {
        while(m-k>=1&&cross(p[i]-tubao[m-1],tubao[m]-tubao[m-1])>0) m--;
        tubao[++m]=p[i];
    }
    m--;
    return m;
}

int main()
{
    int cas,n;
    scanf("%d",&cas);
    while(cas--)
    {
        scanf("%d",&n);
        for(int i=1;i<=n;i++) p[i].read();
        int k=convex_hull(p,n,tubao);
        tubao[k+1]=tubao[1];

        bool flag=true;
        double tmp=(n-2.0)*pi/n;

        for(int i=1;i<=k-1;i++)
        {
            Point a=tubao[i+1]-tubao[i],b=tubao[i+2]-tubao[i+1];
            double cosang=dot(a,b)/(dis(a)*dis(b));
            double ang=acos(cosang);
            ang=pi-ang;
            if(dcmp(ang-tmp)!=0) {flag=false;break;}
        }
        if(flag) printf("YES\n");
        else printf("NO\n");
    }
    return 0;
}