Try factoring this first.
264k = 132*2k = 11*12*k = 11*3*2*2*k
To get a perfect square, you are going to have to have an even number of prime factors.
You have one 11 and one 3. You are going to have to do something about those two.
k = 11 * 3 <<<<< ======= answer.
Now put that into 264k and you get 11 * 3 * 2 * 2 * 11 * 3 which is a perfect square. 11^2 * 3^2 * 2^2 = 4356
The square root of 4356 = 66
4356 is a perfect square when 33 = k.