q = parse(Int,readline()) 
r = readdlm(STDIN)
row = 0
for query = 1:q
    row += 1
    n = r[row,1]
    answer = "YES"
    if n < 3
        row += n
    else
        row += 1
        x1, y1 = r[row,:]
        row += 1
        x2, y2 = r[row,:]
        vec1 = [x2-x1,y2-y1]
        for i = 3:n
            row += 1
            x, y = r[row,:]
            vec2 = [x-x1,y-y1]
            dv = dot(vec1,vec2)
            if dv != 0 && dv != norm(vec1) * norm(vec2)
                row += n - i
                answer = "NO"
                break
            end
        end
        println(answer)
    end
end