Explanation:
that is really a problem ?
come on !
you know, the area of a square is side length × side length = length²
that is basically all of us learn as the very first thing when we are learning about squaring and multiplication.
how do we get the regular side length out of length² ?
we pull the square root. you have a calculator (at least on your computer, cell phone,...).
sqrt(121) = .... .... .... 11 ! tada !
and the perimeter of a square ... you really have to ask ?
it is the way all around the whole square. you need to go along every one of the 4 sides.
so, it is side length × 4 = 11×4 = 44 cm
again - you really needed help with THAT ?