Answer: 300x200
Step-by-step explanation: First of all...Your perimeter equals 2x+3y. X=length, y=width.
2x+3y=1200
3y=1200-2x
y=400-(2/3)x
y=400-(2/3)x
Your Area = xy=x(400-2x/3)=400x-2^2/3
dA/dx=400-4x/3=0
4x/3=400
4x=1200
x=300ft length
y=400-(2/3)(300)=200ft
I hope this helps you!
