Answer:
△PQR and △RST are not similar.
Explanation:
In triangle △PQR, two known interior angles are 34° and 80°. So the measure of third angle is

In triangle △RST, two known interior angles are 24° and 90°.

Two triangles are similar if their corresponding angles are same and the corresponding sides are proportional.
Since the angles of △PQR and △RST are not same, therefore we can say that the △PQR and △RST are not similar.