Question 374234
The formula to use is {{{s = r*theta}}}, where s  =arc length, r = radius, and {{{theta}}} = angle in radians.  {{{theta = 20*(pi/180) = pi/9}}}radians.  The radius of the flywheel is 8inches.  Thus {{{s = 8*(pi/9) = 8pi/9}}}inches, approximately 2.79 inches.