Question 1014500
1/2 perimeter is 18 meters. 
Since L+W = 18, we can substitute and say L = 18-W and the area, A = (W)(18-W)

Distributing, we get A= 18W-W^2 which is a parabola, with a shape that opens down. Now, the X intercepts are 0 and 18, which is a fence with no space in between. The vertex, or maximum area occurs at 9, the midpoint between these zeros. 

At 9 x 9 you get an area of 81, 

From this, you should learn that the maximum area you can get given a perimeter of a rectangle is to form a square.