Help i can’t do this

Question

A factory is to be built on a lot that measures 80m by 60m. A lawn of uniform width and equal in area to the factory must surround the factory. What dimensions must the factory have

Answer 1

80 x 60 = 4800

 

4800/2 = 2400

 

2400 = 60 x 40, which takes 20 feet off both the length and width.

 

60 m x 40 m