Answer : $1,174.70
A circular pool has diameter of 18 ft will have a uniform 4 ft concrete walkway around it.
Diameter = 18ft . So radius = [tex]\frac{18}{2} = 9ft[/tex]
Area of circular pool = [tex]\pi r^2= 3.14 *9*9= 254.34 ft^2[/tex]
Radius of the pool with concrete = 9 + 4= 13
Area of circular pool with concrete= [tex]\pi r^2= 3.14 *13*13= 530.66 ft^2[/tex]
Now surface area of concrete = area of pool with concrete - area of pool
Surface area = 530.66 - 254.34 = 276.32 square feet
the concrete cost $4.25 a square foot of surface area
So the cost for the concrete = 276.32 * 4.25 = $ 1174.36
We used the approximate value of pi that is 3.14 . so we got approximate answer
The option close to our answer is $1,174.70
$1,174.70 is the cost for the concrete