Respuesta :

The formula for the circumference of a circle is [tex]\pi d[/tex].

In a:

The radius is 8 cm.

Therefore the diameter (d) would be 16cm (8 * 2)

Hence, the circumference is [tex]16\pi[/tex]

In b:

The diameter is already given: 13 in.

Thus, the circumference is [tex]13\pi =40.84[/tex] (2dp)