To get the size of the pool we proceed as follows:
let the width be w
the length will be 2w-3
thus given that the perimeter is 54 ft then the dimensions of the pool will be:
P=2(L+W)
thus
54=2[(2w-3)+w]
54=2(3w-3)
54=6w-6
54+2=6w
hence
60=6w
w=10
hence
length =2(10)-3=17
width=10
