somebody please help its due today thank you

Answer:
approximately 52.752 or 16.8 [tex]\pi[/tex]
Step-by-step explanation:
a) we know the diameter so we can use the formula r=d/2 to solve for the radius
b)16.8/2 =8.4
2. Then we substitute into the equation
a)2[tex]\pi[/tex]r
b)2[tex]\pi[/tex](8.4)
c)52.752 or 16.8 [tex]\pi[/tex]