Area is length * width
We want to maximize the area.
We also know he has to cover 3 sides with 1792 feet of fencing.
Let one length (side) be the river, so we have:
2 width sides
1 length sides
Thus, we can write:
2w + l = 1792
or
l = 1792 - 2w
Area = l * w
Substituting, we get: