Answer:
550 square feet
Explanation:
There are 4 areas where the pool deck is situated on:
Top, Left, Right, and Bottom of the pool.
So if the deck is 5 feet wide:
Top = (35 feet * 5 feet) = 175
Bottom = (35 feet * 5 feet) = 175
Left = (20 feet * 5 feet) = 100
Right = (20 feet * 5 feet) = 100
175 + 175 + 100 + 100 = 550 square feet