Please help I will give brainiest I need your help

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)

70

step-by-step explanation:

2*5=10

4*15=60

60+10=

70