Question

Quem sabe Resolver essa?

Answer 1

$A_{c} = \pi r^{2}= \pi ( \frac{5}{2})^{2}= \frac{25 \pi }{4} cm^{2} \\ \\ \\ A_{c} = \pi .4^{2}=16 \pi cm^{2} \\ \\ \\ A _{sc} = \frac{ \alpha . \pi .r^{2}}{360 ^{o} } = \frac{30 ^{o}. \pi .5^{2}}{360 ^{o} } = \frac{25}{12} \pi cm^{2} \\ \\ \\ A _{cc} = \pi (R^{2}-r^{2})= \pi .(5^{2}-3^{2})= \pi .(25-9)=16 \pi cm^{2}$