1. The problem is to find the square root of 157. 2. The square root of a number $x$ is a value $y$ such that $y^2 = x$. 3. Since 157 is not a perfect square, we approximate the square root. 4. We know $12^2 = 144$ and $13^2 = 169$, so $\sqrt{157}$ is between 12 and 13. 5. Using a calculator or estimation, $\sqrt{157} \approx 12.53$. 6. Therefore, the square root of 157 is approximately $12.53$.