\[\boxed{\mathbf{4.62}}\]
\[a^{2} + b^{2} = c^{2}\]
\[Проверим:\]
\[3^{2} + 4^{2} = 5^{2}\]
\[9 + 16 = 25\]
\[25 = 25.\]
\[Верно.\]
\[\textbf{а)}\ 6^{2} + 8^{2} = 10^{2}\]
\[36 + 64 = 100\]
\[100 = 100\]
\[\rightarrow выполняется.\]
\[\textbf{б)}\ 12^{2} + 13^{2} = 15^{2}\]
\[144 + 169 = 225\]
\[313 \neq 225 \rightarrow не\ выполняется.\]
\[Пример:\ \ \]
\[a = 5;\ \ b = 12;\ \ c = 13.\]
\[5^{2} + 12^{2} = 13^{2}\]
\[25 + 144 = 169\]
\[169 = 169.\]