Kindly refer to attachment for solution.
Hope it helps ^_^
Answer:

Step-by-step explanation:
<em>Hey there!</em>
Well if the length is 18 and 3 inches we need to find the sum of both lengths,
18ft 3in + 18ft 3in = 36ft 6in
Width- 10ft 8in + 10ft 8in = 20ft 16 in -> 21ft 4in
l + w = 57ft 10in
<em>Hope this helps :)</em>
D. The answer has to be 2,000, eliminating A and C. B doesn't even use the original equation, as well as incorrectly solving the method, so D is the correct answer, even if you don't understand the principles.