Question 824393
If we can find the side length of the square we can
find the area and perimeter.

Let s = the side length of the square.

{{{s^2 + s^2 = 15^2}}}
{{{2s^2 = 15^2}}}
{{{2s^2 = 225}}}
{{{s^2 = 225/2}}}
{{{s = sqrt(225/2)}}}
The area = {{{sqrt(225/2) * sqrt(225/2)}}} = 225/2 = 112.5 sqft
The perimeter = {{{4*sqrt(225/2)}}}ft