Answer:
160 cm.
Explanation:
First you want to find the length which is 60 cm. then you want to multiply it by 2 because there are two sides that are 60 cm and you get 120. Next you find the width which is 20 cm. and multiply it by 2and you get 40. Finally you add 120 cm. plus 40 cm. and you get 160 cm.