1 #include <cstdio>
  2 #include <cstring>
  3 #include <cstdlib>
  4 #include <cmath>
  5 #include <ctime>
  6 #include <iostream>
  7 #include <map>
  8 #include <set>
  9 #include <algorithm>
 10 #include <vector>
 11 #include <deque>
 12 #include <queue>
 13 #include <stack>
 14 using namespace std;
 15 typedef long long LL;
 16 typedef double DB;
 17 #define MIT (2147483647)
 18 #define MLL (1000000000000000001LL)
 19 #define INF (1000000001)
 20 #define For(i, s, t) for(int i = (s); i <= (t); i ++)
 21 #define Ford(i, s, t) for(int i = (s); i >= (t); i --)
 22 #define Rep(i, n) for(int i = (0); i < (n); i ++)
 23 #define Repn(i, n) for(int i = (n)-1; i >= (0); i --)
 24 #define mk make_pair
 25 #define ft first
 26 #define sd second
 27 #define puf push_front
 28 #define pub push_back
 29 #define pof pop_front
 30 #define pob pop_back
 31 #define sz(x) ((int) (x).size())
 32 inline void SetIO(string Name)
 33 {
 34     string Input = Name + ".in";
 35     string Output = Name + ".out";
 36     freopen(Input.c_str(), "r", stdin);
 37     freopen(Output.c_str(), "w", stdout);
 38 }
 39 
 40 inline int Getint()
 41 {
 42     char ch = ‘ ‘;
 43     int Ret = 0;
 44     bool Flag = 0;
 45     while(!(ch >= ‘0‘ && ch <= ‘9‘))
 46     {
 47         if(ch == ‘-‘) Flag ^= 1;
 48         ch = getchar();
 49     }
 50     while(ch >= ‘0‘ && ch <= ‘9‘)
 51     {
 52         Ret = Ret * 10 + ch - ‘0‘;
 53         ch = getchar();
 54     }
 55     return Flag ? -Ret : Ret;
 56 }
 57 
 58 const int N = 110;
 59 struct Point
 60 {
 61     int x, y;
 62 } Arr[N];
 63 int n;
 64 
 65 inline void Solve();
 66 
 67 inline void Input()
 68 {
 69     int TestNumber = Getint();
 70     while(TestNumber--)
 71     {
 72         n = Getint();
 73         For(i, 1, n)
 74         {
 75             Arr[i].x = Getint();
 76             Arr[i].y = Getint();
 77         }
 78         Solve();
 79     }
 80 }
 81 
 82 inline LL Sqr(int x) {
 83     return 1LL * x * x;
 84 }
 85 
 86 inline int Multi(const Point &O, const Point &A, const Point &B)
 87 {
 88     int X1 = A.x - O.x, X2 = B.x - O.x, Y1 = A.y - O.y, Y2 = B.y - O.y;
 89     return X1 * Y2 - X2 * Y1;
 90 }
 91 
 92 inline LL GetDist(const Point &A, const Point &B)
 93 {
 94     return Sqr(B.x - A.x) + Sqr(B.y - A.y);
 95 }
 96 
 97 inline bool Compare(const Point &A, const Point &B)
 98 {
 99     int Det = Multi(Arr[1], A, B);
100     if(Det) return Det > 0;
101     LL Dist1 = GetDist(Arr[1], A), Dist2 = GetDist(Arr[1], B);
102     return Dist1 < Dist2;
103 }
104 
105 inline void Solve()
106 {
107     For(i, 2, n)
108         if(Arr[i].x < Arr[1].x || (Arr[i].x == Arr[1].x && Arr[i].y < Arr[1].y))
109             swap(Arr[i], Arr[1]);
110     sort(Arr + 2, Arr + 1 + n, Compare);
111     
112     Arr[n + 1] = Arr[1], Arr[n + 2] = Arr[2];
113     bool Flag = 0;
114     int Tmp, Dist;
115     For(i, 1, n)
116     {
117         int Det = Multi(Arr[i], Arr[i + 1], Arr[i + 2]);
118         LL Dist1 = GetDist(Arr[i], Arr[i + 1]);
119         LL Dist2 = GetDist(Arr[i + 1], Arr[i + 2]);
120         if(Det <= 0 || Dist1 != Dist2)
121         {
122             puts("NO");
123             return ;
124         }
125         if(Flag)
126         {
127             if(Tmp != Det || Dist1 != Dist)
128             {
129                 puts("NO");
130                 return ;
131             }
132         }
133         else Flag = 1, Tmp = Det, Dist = Dist1;
134     }
135     puts("YES");
136 }
137 
138 int main()
139 {
140     Input();
141     //Solve();
142     return 0;
143 }