\( \Large l_{1} \) = 20 cm, \( \Large A_{1} \) = 200 sq cm

\( \Large b_{1} \) = \( \Large \frac{200}{20} \) = 10 cm

Now,\( \Large A_{2} \) = \( \Large 200\times 6/5 \)= 240 sq cm

\( \Large b_{2} \) = 10 cm

\( \Large l_{2} \) = \( \Large \frac{240}{10} \) = 24 cm

Perimeter of new rectangle = 2(\( \Large l_{2}+b_{2} \))

= 2(24+10)= \( \Large 2\times 34 \)=68cm.