Description for Correct answer:
Let the radius of circle = r cm

According to the question,

Area of sector = \( \Large 77 cm^{2} \)

\( \Large \frac{\theta}{360 degree}\times \pi r^{2} \)=77 => \( \Large \frac{45 degree}{360 degree}\times \pi r^{2} \)=77

=> \( \Large r^{2}=\frac{77\times 7\times 8}{22} \)=> r=14 cm