Correct!
 

The correct answer is K.


The rectangle is 3 inches by 6 inches, so the area is 3(6) = 18 square inches.
 

F. If the area were 6, then l = 6/3 = 2, but this length isn't twice the width.
 

G. If the area were 9, then l = 9/3 = 3, but this length isn't twice the width.
 

H. If the area were 12, then l = 12/3 = 4, but this length isn't twice the width.
 

J. If the area were 15, then l = 15/3 = 5, but this length isn't twice the width.