Find \(x\)
\begin{align}5^2+12^2 & = x^2\\
\sqrt{169} & =x\\
So \quad x & =13
\end{align}
\begin{align}x^2+36^2 & = 39^2\\
x^2 & =39^2-36^2\\
x & =\sqrt{225}\\
So \quad x & =15
\end{align}
\begin{align}12.5^2+x^2 & = 32.5^2\\
x^2 & = 32.5^2-12.5^2\\
x & = \sqrt{900} \\
So \quad x & =30
\end{align}
\begin{align}(10\sqrt{5})^2+(24\sqrt{5})^2 & = x^2\\
x^2 & =500+2880\\
x & = \sqrt{3380}\\
So \quad x & =26\sqrt{5}
\end{align}