Consider the diagram shown below.
If ΔART≅ΔPEN,
For ASA criteria, two angles and the side between them must be equal.
Therefore,
AT=PN (given)
So,
∠A=∠P
∠T=∠N
For SAS criteria, two sides and the sideangle between them must be equal.
Therefore,
∠T=∠M (given)
So,
RT=EN
PN=AT
For SSS criteria, all three sides must be equal.
Therefore,
AR=PE
RT=EN
AT=PN
Hence, using these conditions we can show that ΔART≅ΔPEN.