The word usage in last sentence of the question is not well presented. However, I can understand that you intend to solve for the width of the park
Answer:
[tex]Width = 2\ km[/tex]
Step-by-step explanation:
Given
[tex]Length = \frac{3}{8}km[/tex]
[tex]Area = \frac{3}{4}km^2[/tex]
Required
Determine the Width
For a rectangle:
[tex]Area = Length * Width[/tex]
Substitute for Area and Length
[tex]\frac{3}{4} = \frac{3}{8} * Width[/tex]
Multiply both sides by [tex]\frac{8}{3}[/tex]
[tex]\frac{8}{3} * \frac{3}{4} = \frac{3}{8} * \frac{8}{3}* Width[/tex]
[tex]\frac{8}{3} * \frac{3}{4} = Width[/tex]
[tex]\frac{24}{12} = Width[/tex]
[tex]2 = Width[/tex]
[tex]Width = 2\ km[/tex]
