Answer :
[tex]Area\ of\ square:\\\\
A=x^2\\x-side\ of\ square\\\\\
500=x^2\ \ | \sqrt{}\\\\
x=\sqrt{500}=\sqrt{5*100}=\sqrt{5}*sqrt{100}=10\sqrt{5}\approx22,4\\\\The\ length\ of\ wood\ trim\ should\ be\ equal\ to\ 22,4inch.[/tex]