I can’t answer anything from my side so I will guide you the best I can! Measure the highlighted lines on the image. Then record the numbers into the correct areas(length,width,height). Then multiply all of the numbers above. That’s how you answer question 3. I’m sorry that I can’t do much more on my side.
Given dimensions of a rectangular garden are:
length = 2(x+6) feet
width = 3.5x feet
using the distributive property on length we get, length = 2x+12
Perimeter of a rectangle is 2(length+width)
So, P = 2(2x+12+3.5x)
Solving it we get,
P = 2(5.5x +12) ..............adding like terms
P = .............multiplying and adding
P = 11x+24
So, perimeter is 11x+24 feet. This value of fencing will be needed.