I found width=13.72 ft and length=43.72 ft.
Call one dimension of the rectangle x, the other will be x+30
You want an area A=600 ft^2 but A=length x width=x*(x+30)=600
Rearranging you get:

solving this quadratic equation you get a negative solution and a positive one that gives your result.
6,12,18,24,30,36,42,48,54
I believe it is 8,000 grams :).
Answer:
J) 110.88 mm^2
Step-by-step explanation:
height =6.93x2=13.86
Area=13.86x16x0.5=110.88