According to the question,

\( \Large \frac{\sqrt{3}}{4}a^{2}= 3\sqrt{3} \)

=> \( \Large \frac{1}{4}a^{2} \)=3 => \( \Large a^{2}=3\times 4 \)

a=\( \Large 2\sqrt{3} \)

Required perimeter=3a=\( \Large 3\times 2\sqrt{3} \)

=\( \Large 6\sqrt{3} \)