In the figure below, $\mathrm{C}$ is the midpoint of $\overline{\mathrm{EA}}, \Varangle \mathrm{E}$ and $\Varangle \mathrm{A}$ are right angles, and $\mathrm{x} \mathrm{PCE}$
and $\Varangle \mathrm{ACN}$ are vertical angles.
(FIGURE CANT COPY)
Why is $\triangle \mathrm{PEC} \cong \triangle \mathrm{NAC} ?$