import math
t = int(input())
for t1 in range(t):
    n = int(input())
    d = {}
    a = []
    for t2 in range(n):
        x,y = input().split(' ')
        x,y = [int(x),int(y)]
        a.append((x,y))
        
        
    for i in range(n):
        for j in range(n):
            if(a[i]!=a[j]):
                dis = ((a[i][0]-a[j][0])**2)+((a[i][1]-a[j][1])**2)
                x = round(math.sqrt(dis),1)
                d[x] = d.get(x,0)+1
    if(len(d.keys())>2):
        print("NO")
    else:
        print("YES")