Respuesta :

Answer:

6 feet long

Step-by-step explanation:

Perimeter = (2 * length) + (2 * width)

18 = (2 * length) + (2 * 3)

18 = (2 * length) + 6

2 * length =18 - 6

2 length = 12

length = 12/2

length = 6

Hope this helps!

Pls mark brainliest :)