The circumference of a circle is [tex]2 \pi r[/tex] since the radius is half of the diameter we can substitute the diameter instead of using 2r. So we get [tex] \pi d[/tex] The we can substitute the given diameter, which is 5 and multiply it by [tex] \frac{22}{7} [/tex] and get [tex] \frac{110}{7} [/tex].