$3.6 \sqrt{3}$
\(\boxed{6.24}\)
Step 1 :Calculate the square root of 3: \(\sqrt{3} \approx 1.732\)
Step 2 :Multiply the square root of 3 by 3.6: \(3.6 \times 1.732 \approx 6.24\)
Step 3 :\(\boxed{6.24}\)