Question

2.

Answer 1

The answer in here is 20ft and here is how you can get to this answer:
If we place the tree at the origin then we can say that
the bottom-left tree is at (-3,-2) 
the top-right tree is at (4,1) 
so the base of the rectangle is 7 
the height is 3 
Taking into account all the details then 
perimeter = 2(7) + 2(3) = 20
Hope this is good enough for you