Recognize that the fencing will encompass an area
that is made up of a curved arc that is half of a
circle plus a straight portion that is the diameter.
We will be adding the arc length plus the diameter
to get the total perimeter of the garden.
d=30 feet...........diameter of circle
θ=180º...............central angle of a semicircle
A=(θº/360º)πd...arc length of a sector
P..........................total perimeter
So let's write our equation for total perimeter...
P=A+d..................................total perimeter equals
arc length plus diameter
=(θº/360º)πd + 30
=(180/360)(3.14)(30) + 30...substitute for variables
=(1/2)(3.14)(30) + 30...........simplify
=47.12 + 30
∴ P=77.12 feet
Now let's calculate the total fencing cost...
$TOT=P x ($cost per foot)
=77.12 x $9.25
∴ $TOT=$713.40
Inactive Tutor
01/21/16