The formula for arc length which is measured in units not degrees is [tex] \frac{ \beta }{360} *2 \pi r[/tex]. Our central angle is 60 and our radius is 6. Of course the 2 pi r in our formula is already given to us as 12 pi. So we sub in accordingly: [tex] \frac{60}{360}*12 \pi [/tex] and when you do that math and multiply in pi, you get that the arc length that is intercepted by that 60 degree angle is 6.28 units.