Question

is it possible to find a side length that would be perfect for a square with an area of 45 square units?

Answer 1

If a square has an area of 45 square units its side has a length of

$s=\sqrt{45} = 3 \sqrt{5}$

units.  Is that a perfect length?  I don't know, but I know it's perfect for a square whose area is 45.