Question

What is the arc length on a circle radius=3pi that is intercepted by a central angle of 9pi?

Answer 1

9pi in terms of radians is the same as 1pi, which is half of a revolution.

So you have a 180 degree angle, so the only arc length you have is half of the perimeter.

Answer 2

Arc length on a circle is given as
\[s=r \theta \]
\[s= 3 \pi \times 9 \pi = 27 \pi^2\]

Answer 3

thank you