Explanation:
let w = width
length = 3w-2
perimeter = 2*length + 2*width
perimeter = 2(3w-2) + 2w
perimeter = 6w - 4 + 2w
perimeter = 8w - 4
perimeter = 124 inch
8w - 4 = 124inch
+4 to each side
8w = 128inch
divide each side by 8
w = 16
length = 3w-2
= 3(16) - 2
length = 46 inch