A sector of 120, cut out from a circle, has an area of 667cm2 . Find the radius of the circle ?

Let the radius of the circle be r cm. Then, 

$\frac{120}{360}\mathrm{\pi r}2=\frac{66}{7}$ 

$r2=\frac{66}{7}*\frac{7}{22}*3$ 

r=3.