1 : What postulate or theorem can be used to prove △PQR ~ △STU ?? Angle-Angle (AA) Similarity Postulate

Side-Side-Side (SSS) Similarity Theorem

Side-Angle-Side (SAS) Similarity Theorem

2 : Are the triangles similar?

No. The triangles are not similar.

Yes, by using Angle-Angle (AA) Similarity Postulate

Yes, by using Side-Angle-Side (SAS) Similarity Theorem

Yes, by using Side-Side-Side (SSS) Similarity Theorem

Firat slide is for #1, and second one is for #2