Question 288227
P = 40
P = 2(L + W)
L = 2W + 2
P = 2(2W + 2 + W)
P = 2(3W + 2)
P = 6W + 4 
40 = 6W + 4 | subtract 4 from each side:
36 = 6W     | divide each side by 6 
W = 6 <br>
L = 2*6 + 2 = 14
2(14 + 6) = 40 and bob's your uncle!