The arc length is related to the angle and length of the radius of the circle via the equation
[tex]S=r\theta[/tex]This is a unit circle, hence, r = 1. The angle is given as 1.5 radians or can be written as 1.5π. Hence, the length of the intercepted arc is computed as
[tex]\begin{gathered} S=(1)(1.5\pi) \\ S=1.5\pi \end{gathered}[/tex]