Respostas

2014-01-29T12:26:35-02:00
5 metros ~> 500 cm 
2 m ~> 200 cm

 \frac{R}{8} =  \frac{500}{200}  \\  \\ R =  \frac{8.500}{200}  \\  \\ R= \frac{4000}{200} = 20 cm

A  = \pi .R ^{2}  \\ A = 3,14.20 ^{2}  \\ A=3,14.400 \\ \boxed{A = 1256cm ^{2}}
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