The formula for the area of a square is:
A = Length x Height
You know that all the sides of a square are equal to each other. That means that all the values in the area formula should be the same.
Knowing this you can divide the area by 2 since only two sides are involved in the area formula
225.6004 / 2 = 112.8002
^^^Each side in the square playground is 112.8002 meters
Hope this helped!
~Just a girl in love with Shawn Mendes