Answer:
#7 = 53.41
#8 = 18.85
#9 = 87. 96
Step-by-step explanation:
The formula for Circumfrance of a circle is: C=2 π r
So lets do #7:
17/2 (the radius is 1/2 of the diameter)
R= 8.5 (now plug in)
C= 2 π 8.5
C=17π
Now repeat on 8 and 9
8:
C= 2 π 3
C=6π
c= 18.85
9:
C= 2 π 14
C= 28π
C= 87.96