The perimeter of rectangular is .
Consider length of rectangular is and width of the rectangular is
,then perimeter of rectangular is
.
But one side width has covered by highway,hence the perimeter is .
The area of rectangle is
.
if ,
.
Substitute in the equation
.
.
The area of rectangle is .
Find the maximum area of rectangle.
\The maximum area of rectangle occurs when the length is maximum.
\ is the form of general quadratic equation.
Therefore and
.
The maximum area occurs at .
The maximum length is .
Substitute in the function
to get the maximum area.
The maximum area is .
The maximum area is .