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)
