Answer:
The answer is "[tex]\bold{100\ ft \times 200\ ft}[/tex]"
Step-by-step explanation:
A = area of the pigpen
x = its perpendicular length of the sides of the stone wall
Maximize function:
[tex]\to A = x (400-2x)\\\\Where\ \ 0<x<200[/tex]
So, the size of pigpen is = 100 ft by 200 ft that is (perpendicular and parallel to wall), that's why the answer is "[tex]\bold{100\ ft \times 200\ ft}[/tex]"
