Answer:
The cost of fertilizing the field is [tex]\$437.96[/tex]
Step-by-step explanation:
we know that
The area of the figure is equal to the area of the rectangle plus the area of a complete circle (two semicircles)
Step 1
Find the area of the rectangle
The area of rectangle is equal to
[tex]A=LW[/tex]
where
L is the length side of rectangle
w is the width side of the rectangle
In this problem we have
[tex]L=125\ yd[/tex]
[tex]W=D=40\ yd[/tex]
substitute
[tex]A=125*40=5,000\ yd^{2}[/tex]
Step 2
Find the area of the circle
The area of the circle is equal to
[tex]A=\pi r^{2}[/tex]
where
r is the radius of the circle
In this problem we have
[tex]r=40/2=20\ yd[/tex]
substitute
[tex]A=\pi (20)^{2}=1,256.64\ yd^{2}[/tex]
Step 3
Find the area of the figure
Adds the area of rectangle and the area of the circle
[tex]5,000\ yd^{2}+1,256.64\ yd^{2}=6,256.64\ yd^{2}[/tex]
Step 4
Find the cost
Multiply the total area by [tex]0.07 \frac{\$}{yd^{2} }[/tex]
so
[tex]6,256.64*0.07=\$437.96[/tex]