Can I double check this I'm not entirely sure if my answer is correct.
What is the smallest perfect square that has a factor of 90.
8100?
90 = 2x3x3x5
since each pair of equal factors produces a perfect square, we have 3x3, a perfect square.
So all we need is another 2 and another 5
How about 2x2x3x3x5x5 = 900
900 = 30^2 , so it is a perfect square, and it is divisible by 90