Use formula for the length of the arc:
[tex] \text{Arc Length} = (\theta\cdot \dfrac{\pi}{180^{\circ}}) \cdot r [/tex], where [tex] \theta [/tex] is central angle.
Substitute [tex] \theta [/tex] and r=3 into formula:
[tex] \text{Arc Length} = (\theta\cdot \dfrac{\pi}{180^{\circ}}) \cdot r=(70^{\circ}\cdot \dfrac{\pi}{180^{\circ}})\cdot 3=\dfrac{7}{6}\pi [/tex].
Answer: [tex] \text{Arc Length} =\dfrac{7}{6}\pi [/tex].
