#1**+1 **

Area of square = \(s^2\) where, \(s\) is the side length of the square.

\(81=s^2\)

\(9=s\)

s must be positive since it is a side length, so the negative root of 81 is rejected.

Perimeter= \(4s\)

Perimeter=\(4(9)=36\) \(inches\)

.Guest Feb 6, 2020

#2**+1 **

Well, let's make the area "a".

And to calculate an area is a^2.

So if we want to find just one side, we can square root it:

sqrt"a".

In this case, it's sqrt81 = 9.

Which means that one side is 9.

To find the perimeter of a square, we multiply by 4, or we can add up one side 4 times:

9*4 OR 9+9+9+9 = 36.

Perimeter = 36

AnimalMaster Feb 6, 2020