\[ \begin{array}{l}\sqrt{45} \\ \sqrt{45} \approx \square \text { (Round to four decimal places as needed.) }\end{array} \]

To find \(\sqrt{45}\), we can simplify it first. Notice that \(45 = 9 \times 5\), so we have \(\sqrt{45} = \sqrt{9 \times 5} = \sqrt{9} \cdot \sqrt{5} = 3\sqrt{5}\). Next, calculate \(\sqrt{5}\). The approximate value is 2.2361. Therefore, \(3\sqrt{5} \approx 3 \times 2.2361 = 6.7083\). So, \(\sqrt{45} \approx 6.7083\) when rounded to four decimal places.