Remember that the formula for the circumference,
, of a circle is:

In this case, we are not given the diameter. However, remember that the diameter is equivalent to two times the radius of a circle. Thus,
,
and we can say the circumference of our circle is:

The circumference of our circle is 50.24 units.
<em>Also, a little side note not relating to the question:</em>
<em>Remember that
is spelled as "pi" not "pie." Pie is a dessert, while pi is a mathematical constant.</em>