Respostas

  • Usuário do Brainly
2014-07-24T16:02:08-03:00
Seja φ o ângulo do setor circular.

φ = x / l
φ = x / 28 rad

π  ~~ 2π rad
40 ~~~ x/28 rad

80 
π  rad =x³π /28 rad

x³=28.80
x³=2240
x= 13,0,84 aprox  [e]