If the diameter of a tennis ball is 2.6
then the radius will be 1.3 (because the radius f a circle is half of a diameter)
The circumference of a circle is given by any of these two formulae
[tex]\begin{gathered} C\text{ = }\pi D \\ or \\ C\text{ = 2}\pi r \end{gathered}[/tex]Using
[tex]\begin{gathered} \pi D \\ \text{Diameter = 2.6} \\ \pi\text{ = 3.14} \\ \end{gathered}[/tex]C = 3.14 x 2.6
C = 8.164 inches
