Given width is 24 less than length. W=L-24 Perimeter = 2(W+L)=2(L-24+L)=4L-48 But we're also given perimeter = 172' Therefore 4L-48=172 solve for L 4L=172+48=220 L=55' W=55-24 = 31' Check: Perimeter = 2(W+L)=2(31+55)=2*86=172' good!
Answer: The dimensions of the garden are 31' * 55'