I drew the parallelogram in the picture you can see below. With the data of the exercise we realize that the parallelogram is a rectangle. So, with 2 sides of 11 feet long and the other side of 8 feet long, the last side have to measure 8 feet long.
Your answer is correct... it's no.3 ... but if you multiply a inequality by a negative value the inequality sign changes.. like if you habe greater than it'll be less than... Keep that in mind too