We have a square garden of 400 square foot.
The area of a square is:
where x: side length.
In this case:
The perimeter of the square is the sum of the lengths of the sides of the square. As they are all equal, we can write:
The fencing is priced at $1.50 per foot. If we add the 7% sales tax to this price we get:
The fencing will be installed in all the perimeter (80 ft).
We can calculate the total cost by multiplying the sales price ($1.605 per foot) and the perimeter (80 ft):
Answer: the fencing will cost a total of $128.40