please help I will give brainiest I need your help!!!!

Answer:
Step-by-step explanation:
∠OAB is 90 degrees, tangent and a radius met at 90 degree angle
∠OCB=90 degrees, tan and radius meet at 90 degrees angle
OB=12
find angle BOC:
triangle BOA is right angle triangle:
cos(AOB)=adj/hyp=7/12=54.33
angle B= 180-(90+54.33)=35.67
angle COB=54.33 equal to angle AOB
angle AOC=54.33+54.33=108.66
the sum of angles of circle =360
360-108.66= 251.34( exterior angle at the center AOC)
length of the arc= angle (251.34 degrees*7)
convert degrees to radians=4.386 (251.34/π)
length=r*angle in radian=4.386*7=30.71
( i hope this is the answer)