Answer: The correct answer is 20 inches for the perimeter.
At the beginning the length and width are 8 in by 10 in. We are going to add 0.5 inches on each side of the length and width. That means that each of the sides will increase by 1 inch.
Our new measurements are 9 by 11.
Add up all for sides to find the perimeter.
9 + 9 + 11 + 11 = 20 inches
