1000 yds of fence

Question

x 1000-x
1. Show that the area function to be maximized is A(x) = ( pi + 4 / 16pi) x^2-125x+62500

2. Show that the critical point of A(x) is x=1000pi/pi+4

3. 1000yds of fencing and y>2r, find the values of r and y that maximizes the area of this new region. What is the area of the region?