Question

A circle has a radius of 5.4 m.

Answer 1

Yes it is good job !

Answer 2

$\bf \textit{arc's length}\\\\ s=\cfrac{\pi \theta r}{180}\quad \begin{cases} r=radius\\ \theta =angle~in\\ \qquad degrees\\ ------\\ r=5.4\\ \theta =60 \end{cases}\implies s=\cfrac{\pi (60)(5.4)}{180}\implies s=1.8\pi$

yes, it is correct.