Question 802889
let the width be W
and since the perimeter P of a rectangle = 2L + 2W

then 60 = 2L + 2W
L is given as W + 4
thus 60 = 2(W + 4) + 2W
simplified, 
60 = 2W + 8 + 2W 
60 - 8 = 52 = 4W
52/4 = W