Find the length of the arc.

Answer:
1st option
Step-by-step explanation:
The length of the arc is calculated as
arc = circumference of circle × fraction of circle
= 2πr × [tex]\frac{210}{360}[/tex]
= 2π × 13 × [tex]\frac{21}{36}[/tex]
= 26π × [tex]\frac{7}{12}[/tex]
= [tex]\frac{26\pi (7)}{12}[/tex]
= [tex]\frac{182\pi }{12}[/tex]
= [tex]\frac{91\pi }{6}[/tex]