Question 41041
I am going to guess that this sign is rectangular.
Length(l) = w + 4
Width(w) = w
Length * Width = Area
(w + 4)(w) = 45
w^2 + 4w = 45
w^2 + 4w - 45 = 0
(w + 9)(w - 5) = 0
{{{w = -9}}} or {{{w = 5}}}
Since the width can not be negative, your width is: {{{w = 5}}}
Plug:
Length = w + 4
Length = 5 + 4
Length = 9