#### Answer

8 meters

#### Work Step by Step

Let x be the length of a side of the original square. If the area of the new square is 144 square meters then:
$144=(x+2+2)^2$
Simplify.
$144=(x+4)^2$
Take the square root of each side.
$\sqrt{144}=\sqrt{(x+4)^2}$
Simplify.
$12=x+4$
Subtract 4 from each side.
$12-4=x+4-4$
Simplify.
$8=x$