[tex] \frac{1}{4} \times \pi \times ({radius})^{2} = \\ [/tex]
[tex] \frac{1}{4} \times \pi \times {12}^{2} = \\ [/tex]
[tex] \frac{1}{4} \times \pi \times 144 = \\ [/tex]
[tex] \frac{144}{4} \pi = \\ [/tex]
[tex]36\pi[/tex]
