A city manager wants to add a playground in a new city park. The rectangle below represents the plan for the dimensions of the rectangular playground.

area = x^2 + 18x + 45; Width=W; Length= x+15

a. Find the width (w) of the rectangle if the area of the rectangle is x2 + 18x + 45.
b. Find the dimensions (length × width) and the area of the playground if x = 8 yards.