Answer:
B. [tex] \frac{9}{20}\pi [/tex]
Step-by-step explanation:
Central angle [tex] \theta = 81\degree [/tex]
Radius (r) = 1 unit
[tex] l(\widehat {HJ}) = \frac{\theta}{360\degree} \times 2\pi r[/tex]
[tex] l(\widehat {HJ}) = \frac{81\degree}{360\degree} \times 2\pi r[/tex]
[tex] l(\widehat {HJ}) = \frac{81}{360} \times 2\pi (1)[/tex]
[tex] l(\widehat {HJ}) = \frac{9}{40} \times 2\pi [/tex]
[tex] l(\widehat {HJ}) = \frac{9}{20}\pi [/tex]
