3.
\begin{figure}[h]
\captionsetup{labelformat=empty}
\caption{Figure 1}
\includegraphics[alt={},max width=\textwidth]{6c256e1b-455d-42fb-81f2-a9a8ed1148bc-2_503_801_998_566}
\end{figure}
The parametric equations of the curve \(C\) shown in Figure 1 are
$$x = a ( t - \sin t ) , \quad y = a ( 1 - \cos t ) , \quad 0 \leq t \leq 2 \pi$$
Find, by using integration, the length of \(C\).