We know that the formula for area of a square is A = s² where A = area and s is the length of one side. We know that A = 36 so:
36 = s²
√36 = s
s = ±6
Note that s = -6 is an extraneous solution because you can't have a side length of -6, therefore the answer is s = 6 so the dimensions of the square are 6 cm by 6 cm.
First you find the area of the circle, the formula is A=3.14(radius squared) so in this scenario it’s 3.14(4•4) 4 squared is 16, so now we have 3.14(16) which is 622.976, we round that to get our answer of 623