A farmer has 60m of fencing with which to construct three sides of a rectangular yard connected to an existing fence.
a) if the width of the paddock is x metres and the area inside the yard A square metres, write down the rule connecting A and x.
b) Sketch the graph of A against x.
c) Determine the maximum area that can be formed for the yard.
I didn't exactly understand this, and please keep it to year 11 standards. And I haven't learned calculas yet.