I am trying to solve this triangle: Image of the triangle
But I don't know if my result is correct and don't know the correct way to check it.
My result is 4 using the similarity of triangles this way:
$\begin{gathered}\triangle D C B \cong \triangle E C F \\ \frac{C B}{C F} = \frac{2}{1} \\ C B=2 C F \\ \frac{C D}{C E}=\frac{C B}{C F} \\ C D=8\text { (given) } \\ C E=x \\ C F=y \\ \frac{8}{x} = \frac{2 y}{y} \\ 8 y=2 x y \\ 2 x=8 \\ x=4 \\ C E=4\end{gathered}$