1. Find the side length:

* A square has four equal sides.

* Perimeter = 36 inches

* Side length = Perimeter / 4 = 36 inches / 4 = 9 inches

2. Calculate the area:

* Area of a square = side length * side length

* Area = 9 inches * 9 inches = 81 square inches

Therefore, the area of the square is 81 square inches.