Respostas

2014-03-16T14:15:52-03:00
Raio = Diametro / 2

R = 20 / 2 = 10 m


1 rad ----------  \frac{180^0}{ \pi }  = 60^0   (  considerando π = 3 )
3 rad ---------------x

x = 180°


360° ----------- 2.π . R
180° --------------x

x = π . R  ( Considerar o π = 3 novamente)

 
x = 3 . 10  = 30 m de comprimento 
2014-03-16T14:16:05-03:00
Raio = 10 m

2π rad ---------- 2.π.10
  3 rad ----------    x

 \frac{2 \pi }{3} = \frac{20 \pi }{x}

\frac{1 }{3} = \frac{10 }{x}

x=30 m