The question states "Find the side of a square whose diagonal is 5 feet longer that its side". It seems easy but I'm not sure about my answer. Since I know that a square has equal sides, I assign $x$ and the diagonal is $x+5$. That means that half of a diagonal is $ \sqrt{x^2-(\frac{x+5}{2})^2}$. So I thought that a whole diagonal would equal two of these so $x+5 = 2\sqrt{x^2 - (\frac{x+5}{2})^2}$ and I got $5+5\sqrt{2} ft$. Is this right?
Thank you for your help!