Problema Solution
A garden is in the shape of a square with a perimeter of 36 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 $1.23 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 = 36 ft thus we have:
4a = 36 divide both sides by 4
a = 36/4
a = 9 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(9 + 4) = 4*13 = 52 ft
the total length of the two fences = the length of the first fence (36 ft - the perimeter of the square garden) + the length of the second fence (52 ft)
the total length of the two fences = 36 + 52
the total length of the two fences =88 ft
the material used to build the two fences costs $1.23 per foot thus for 88 ft the cost will be 88 times the unit cost ($1.23 per foot):
88*1.23 = $108.24
the total cost of the fences was $108.24.