notice that, if the diameter is 6 inches, then the radius is half that,
[tex]\bf \textit{arc's length}\\\\
s=\cfrac{\pi r\theta }{180}\quad
\begin{cases}
r=radius\\
\theta =angle~in\\
\qquad degrees\\
------\\
r=3\\
\theta =70
\end{cases}\implies s=\cfrac{\pi \cdot 3\cdot 70}{180}[/tex]
