Answer:
21 feet
Step-by-step explanation:
The pool has dimension 15 feet by 17 feet, which is in the form of a rectangle.
The area of the pool = length × width
= 17 × 15
= 255 square feet
Area of the pool and cement walkway = 483 square feet
Area of walkway = area of pool and walkway - Area of pool
= 483 - 255
= 228 square feet
Let's assume that the cement walkway has equal thickness across its perimeter, so that;
the dimension of the pool and the cement walkway = 23 feet × 21 feet
The width of the cement walkway is 21 feet.