q=int(input())


for i in range(0,q):
    n=int(input())
    l=[]
    for j in range(0,n):
        x,y = raw_input().strip().split(' ')
        x,y = [int(x),int(y)]
        minil=[]
        minil.append(x)
        minil.append(y)
        l.append(minil)
    distancex=abs(l[0][0]-l[1][0])
    distancey=abs(l[0][1]-l[1][1])
    for d in range(1,len(l)):
        newdistancex=abs(l[d][0]-l[d+1][0])
        newdistancey=abs(l[d][1]-l[d+1][1])
        if distancex!=newdistancex:
            print "NO"
            break
        elif distancey!=newdistancey:
            print "NO"
            break
        print "YES"