Figure P'E'AR' is obtained by reflecting the figure PEAR.
Then, congruent sides are
[tex]\begin{gathered} AR\cong AR^{\prime} \\ PR\cong PR^{\prime} \\ AE\cong AE^{\prime} \\ PE\cong P^{\prime}E^{\prime} \end{gathered}[/tex]
Congruent angles are
[tex]\begin{gathered} \angle ARP\cong\angle AR^{\prime}P^{\prime} \\ \angle EPR\cong\angle E^{\prime}P^{\prime}R^{\prime} \\ \angle PEA\cong\angle P^{\prime}E^{\prime}A \\ \angle EAR\cong\angle E^{\prime}AR^{\prime} \end{gathered}[/tex]
Hence, we can say that
[tex]\text{PEAR}\cong P^{\prime}E^{\prime}AR^{\prime}[/tex]
