Answer
$width=36$
and $length = 78$
Work Step by Step
Since we are given that perimeter = 228
Formula to calculate the perimeter of a rectangle is :
Perimeter= 2( Length + Width) or, $P= 2(l+w)$
Here, $l= 2w+6$
Thus, $228= 2 (2w+6+w)$
or, $228=4w+12+2w$
or, $228=12+6w$
Thus, $width=36$
and
$length = 2w+6= 2(36)+6= 78$