Answer:
[tex]13\pi[/tex]
Step-by-step explanation:
[tex]C=2\pi r[/tex]
If the diameter is 13, divide it by 2 to find the radius:
[tex]\frac{13}{2} =6.5[/tex]
Insert into formula:
[tex]2*\pi *6.5[/tex]
Simplify multiplication:
[tex]13\pi[/tex]
Finito.
