Question 1041494
First, represent the variables...
l is for length ; w is for width

l = 3+w
w = w

how to solve it :
(3+w)(w) = 270
w^2 + 3w = 270
w^2 + 3w - 270 =0
(w+18)(w-15)

answer:
l = 3+w(15) = 3+15 = 18
w= 15

therefore,
the length is 18 and width is 15.

:D