Question

What is the arc length of theta equals 2pi/7 and the radius is 3 cm

Answer 1

$\bf \textit{arc's length}\\\\ s=r\theta ~~ \begin{cases} r=radius\\ \theta =angle~in\\ \qquad radians\\ ------\\ r=3\\ \theta =\frac{2\pi }{7} \end{cases}\implies s=3\cdot \cfrac{2\pi }{7}\implies s=\cfrac{6\pi }{7}$

and you can use whatever value for π, some use 3.14, and round it as needed.