we are given
radius is 8
[tex] r=8 [/tex]
length of arc is 2pi
[tex] l=2\pi [/tex]
now, we can use formula
[tex] \theta=\frac{l}{r} [/tex]
where
theta is central angle
[tex] \theta=\frac{2\pi}{8} [/tex]
[tex] \theta=\frac{\pi}{4} radians [/tex]...........Answer
