Answer:
a. r=4
b. 8pi or 25.13 when rounded to nearest hundreth
c. once
d. twice
Step-by-step explanation:
a)
16pi=pi*r^2
16=r^2
4=r
b)
2(4)pi
8pi or 25.13 when rounded to nearest hundreth
c) once
d) twice
