Let's assume
length of rectangle is x
width of rectangle is y
now, we can draw rectangle
now, we can find fencing length
we are given
total fencing length=400
so, we can set them equal
now, we can solve for y
now, we can find area
Area=length*width
we can plug back y
we have to maximise area
For maximising area , firstly we find derivative of area
and then we can set derivative =0 and then we solve for x
so, firstly we will find derivative
now, we can set it to 0
and then we solve for x
now, we can find y
so, dimensions are
length is 100 feet
width is feet.............Answer