Question

What is the radius of a circle with a central angle of 4π7 radians that intercepts an arc of length 12π in.?

Answer 1

$\frac{4 \pi}{7}R=12 \pi \\ \\ \Rightarrow R = \frac{12 \pi \times 7}{4 \pi} \\ \\ \Rightarrow \boxed{ R = 21\ in}$