Question 851429
The diagonal cuts the square into right triangles.
In a right triangle,
{{{a^2+b^2=c^2}}}
{{{a^2+b^2=22}}}
Since it's a square, a and b have the same lengths, so
{{{2a^2=22}}}
Divide each side by 2
{{{a^2=11}}}
Take the square root
a = the square root of 11 (and therefore, b = the square root of 11)
Add the sides together and multiply by 2 to get the perimeter (perimeter is a fence requiring 2 width + 2 length) - since it's a square, just multiply the side by 4.
4 * sq rt of 11 = 13.2665