The area of a sector of a circle with a central angle of 9𝜋/14 rad is 21 m2. Find the radius of the circle. (Round your answer to one decimal place.)
_____ m
A (sector) = (1/2) r^2 θ
21 = (1/2) r^2 ( 9/14)pi
42 = (9/14) pi r^2
42 / [ (9/14 * pi)] = r^2
196 / (3pi) = r^2
14 / sqrt (3pi) = r ≈ 4.6 m
