Answer:
C
Step-by-step explanation:
The arc length is calculated as
arc = circumference of circle × fraction of circle
= 2πr × [tex]\frac{285}{360}[/tex]
= 2π × 18 × [tex]\frac{19}{24}[/tex]
= 36π × [tex]\frac{19}{24}[/tex] ( cancel 36 and 24 by 12 )
= 3π × [tex]\frac{19}{2}[/tex]
= [tex]\frac{57\pi }{2}[/tex] → C
