According to the meaning of the question, it is necessary to enclose a rectangle. If the length of the side of a rectangle perpendicular to the wall is x meters, then the rectangle is against the wall.
The length of one side is 64-2x meters, and the area of the rectangle is S=(64-2x)*x,
To find the maximum value of S, we can calculate the maximum value of 2S, 2S=(64-2x)*2x,
Because (64-2x)+2x=64 is a constant, according to the average inequality, the product of the multiplication of two numbers is the largest when it is equal.
Let 64-2x=2x and x = 16m (width). At this time, 64-2x = 32m (using the length of the wall).
Your idea is absolutely right.