Answer
$\theta$= 0.3927 radian
Work Step by Step
total angle of circle is $2\pi$ radian
number of spoke dividing the circle (n) is 16
angle between the two adjacent spoke is
$\theta ={\frac{2\pi}{16}} $radian
$\theta$= 0.3927 radian
thus ,the angle between adjacent spoke is 0.3927 radian