Problema Solution
A garden is in the shape of a square with a perimeter of 32 feet. The garden is surrounded by two fences. One fence is around the perimeter of the garden, whereas the second fence is 2 feet from the first fence on the outside. If the material used to build the two fences is $1.46 per foot, what was the total cost of the fences?
Answer provided by our tutors
let
a = the length of the side of the square garden
P = 4a is the perimter of the square garden
we also know that P = 32 ft thus we have:
4a = 32 divide both sides by 4
a = 32/4
a = 8 ft
now we can find the length of the second fence that is 2 feet from the first fence on the outside (make a drawing):
4(a + 2*2) = 4(8 + 4) = 4*12 = 48 ft
the total length of the two fences = the length of the first fence (32 ft - the perimeter of the square garden) + the length of the second fence (48 ft)
the total length of the two fences = 32 + 48
the total length of the two fences = 80 ft
the material used to build the two fences costs $1.46 per foot thus for 80 ft the cost will be 80 times the unit cost ($1.46 per foot):
80*1.46 = $116.80
the total cost of the fences was $116.80.