#### Answer

Width = 11
Length = 8 + 11 = 19

#### Work Step by Step

Perimeter = 2(length + width)
Perimeter = 60 feet
Length = 8 + width (given)
Replacing in formula
Perimeter = 2((8 + width) + width)
60 = 2(8 + 2width)
$\frac{60}{2}$ = (8 + 2width)
30 = 8 + 2width
30 - 8 = 2width
22 = 2 width
$\frac{22}{2}$ = 2 width
Width = 11
Length = 8 + 11 = 19