The original rectangle has a perimeter of 16

12.4 / 6.2 = 2

so other side of enlarged rectangle = 1.8 x 2 = 3.6

Perimeter of enlarged rectangle = 2(3.6 + 12.4) = 32

32 feet

Another way to do:

12.4 / 6.2 = 2

SF = 2

The original rectangle has a perimeter of 16

Perimeter of the enlarged rectangle = 16 x 2 = 32

32 feet