Assuming that the park is of rectangular shape, we'll work with the area of rectangle formula:
Area = Length × Width
Given: Length = 9 and Area = 3(3)/(8)
Find: Width = ?
∵ Area = Length × Width
∴ We substitute the Area with 3(3)/(8) and the Length with 9
∵ 3(3)/(8) = 9 × Width
∴ Width = 3(3)/(8) ÷ 9
Converting 3(3)/(8) into an improper fraction:
3(3)/(8) = (27)/(8)
(27)/(8) ÷ (9)/(1) = (27)/(8) × (1)/(9) = (3)/(8)
∴ Width of the dog park = (3)/(8)
Verification: 3(3)/(8) = 9 × (3)/(8)