what is the exact answer in simplest form?

Answer:
[tex]\frac{\pi }{4}[/tex] inches
Step-by-step explanation:
The arc length is calculated as
arc = circumference of circle × fraction of circle
= 2πr × [tex]\frac{45}{360}[/tex]
= 2π × 1 × [tex]\frac{1}{8}[/tex] = [tex]\frac{2\pi }{8}[/tex] = [tex]\frac{\pi }{4}[/tex] inches