A garden is in the shape of a square with a perimeter of 36 36 feet. The garden is surrounded by two fences. One fence is around
the perimeter of the garden, whereas the second fence is 3 3 feet from the first fence on the outside. If the material used to build the two fences is $ 1.32 $1.32 per foot, what was the total cost of the fences
Let L be the length of the first fence surrounding the garden and P its perimeter.
For a square, P = 4L,
So, L = P/4
Since P = 36 feet,
L = P/4
= 36/4
= 9 feet
Let L' be the length of the second fence. Given that second fence is 3 feet away from the first fence, it follows that L' = L + 3
= 9 + 3
= 12 feet.
So, the perimeter of the second fence is P' = 4L'
= 4 × 12 feet
= 48 feet.
So, the total length of the two fences is P" = P + P'
= 36 feet + 48 feet
= 84 feet
Since the cost of the material to build the two fences is $1.32 per foot, the total cost of the fences is cost per foot × total length of fences = $1.32 × 84 = $110.88
