we know that
the circumference of a circle is giving by
[tex]C=2\pi r[/tex]we have
C=30pi
substitute
[tex]\begin{gathered} 30\pi=2\pi r \\ \text{simplify} \\ r=\frac{30}{2} \\ r=15\text{ units} \end{gathered}[/tex]Find the area of the circle
[tex]A=\pi r^2[/tex]substitute the value of r
[tex]\begin{gathered} A=\pi(15^2) \\ A=225\pi\text{ unit\textasciicircum{}2} \end{gathered}[/tex]