A rectangular lot has a river on one side and is fenced off into 3 areas with 752m of fencing. Find the dimensions and its maximum area. Note: There is no fencing along the river

I have:

Perimeter = 752m

Area = l x w

Thats what i have so far, don't know if its right or wrong. Would be gratefull if anyone could tell me if what i have so far looks right, and what/how to do next.