Respuesta :

Answer:

x= 8 feet   (answer : A)

Step-by-step explanation:

hello :

the perimeter is : P= 2(x+y)       y : the length      x : the width

P=40   and  y = 12    calculate : x

2(x+12) =40

divid by 2 :  x+12 =20

x=20-12

x= 8 feet