Step-by-step explanation:
1. If any one side and any one common angle are equal in triangles PQR and PRS, then their corresponding sides are also equal.
2. If two sides and one included angle are equal in triangles PQS and PRS, then their third sides are equal.
3. In triangles PQR and PQS, if one side and one angle are equal, then their corresponding sides and angles are also equal.
4. In triangles PRS and PQS, all three angles are equal.
