Concept:Angles subtended by the same chord in a circle are equal.An angle in a semicircle is always 90∘.Explanation:∠PQT and ∠PRT subtend the same chord PT.Therefore, ∠PRT=∠PQT=33∘.Since RT is a diameter, ∠TPR is the angle in a semicircle.So, ∠TPR=90∘.Consider △PTR.The sum of angles in a triangle is 180∘.Thus, ∠PTR=180∘−(90∘+33∘).∠PTR=180∘−123∘.Hence, ∠PTR=57∘.Answer:∠PTR=57∘Correct option: C.
