Answer:
[tex]A=81\pi\ m^{2}[/tex]
Step-by-step explanation:
Step 1
Find the radius of the circular cross section
we know that
The circumference is equal to
[tex]C=2\pi r[/tex]
we have
[tex]C=18\pi\ m[/tex]
substitute and solve for r
[tex]18\pi=2\pi r[/tex]
simplify
[tex]18=2 r[/tex]
[tex]r=9\ m[/tex]
Step 2
Find the area of the circular cross section
The area of the circle is equal to
[tex]A=\pi r^{2}[/tex]
we have
[tex]r=9\ m[/tex]
substitute
[tex]A=\pi (9)^{2}[/tex]
[tex]A=81\pi\ m^{2}[/tex]
