Respuesta :

Answer: Length = 9 in

Width = 12 in

Step-by-step explanation:

Length L = 3 + W

Perimeter P = 42 in

Perimeter = 2L + 2W

plugin values:

42 = 2(3 + W) + 2W

42 = 6 + 2W + 2W

42-6 = 4W

W = 36 / 4

W = 9  

solve L by substituting the value of W=9 into the equation:

L = 3 + W

L = 3 + 9

L = 12

therefore, the dimensions of the rectangle:

               Length = 9 in

               Width = 12 in

Answer:

Answer:

length = 9 in

width = 12 in

Step-by-step explanation:

You have to use the formula for the perimeter of a rectangle

P=2(l+w)