Final answer:
Angle ∠PTS is a right angle since PS is a diameter, and angles subtended by a diameter in a circle are always right angles according to the Inscribed Angle Theorem.
Step-by-step explanation:
To classify the angle ∠PTS, we need to consider the properties of a circle and the information provided about the angles ∠QRS and ∠QTR. Given that PS is a diameter, any angle that is subtended by a diameter in a circle is a right angle due to the Inscribed Angle Theorem. Therefore, ∠PTS is a right angle.
Even though ∠QRS is given as obtuse and ∠QTR is acute, these angles do not directly impact the classification of ∠PTS because ∠PTS is uniquely determined by the fact that PS is a diameter. Therefore, ∠PTS does not depend on the obtuseness or acuteness of the other angles mentioned.