The length of an arc subtended by a central angle and 2 radii is
Where:
r is the radius
Cita is the central angle in radian
Since the radius of the circle is 8 inches, then
Since the arc is subtended by a central angle of 135 degrees, then
Substitute them in the rule above
The length of the arc is 6pi
We will find it in 2 decimal places
The length of the arc is 18.85 inches