Based on the wording of the question, I believe that the answer allows you to pick more than one. However, there still may only be one answer.
Answer:20
Step-by-step explanation:
Answer:
,
, 
Step-by-step explanation:
The perimeter covered by the electric fence in meters is:

The area of the rectangle is:


Let differentiate the previous equation and equates to zero:

The critical point is:

By the Second Derivative Text, it is proved that critical point lead to a maximum:

The other side of the rectangle is:

The largest area than can be enclosed is:


The dimensions of the triangle are:


I’m supposing you are writing an equation for this. The equation could be written as 6x+10=4y+11.