In the figure, sides QP and RQ of △PQR are produced to points S and T, respectively. If ∠SPR=135∘ and ∠PQT=110∘, find 2∠PRQ.
110∘+∠2=180∘ [since, RQT is a straight line]
⇒∠2=180∘−110∘
⇒∠2=70∘
Also, ∠1+135∘=180∘ [since, QPS is a straight line]
⇒∠1=180∘−135∘=45∘
Also, ∠1+∠2+∠R=180∘ [angle sum property]
⇒45∘+70∘+∠R=180∘
⇒∠R=180∘−115∘=65∘
Therefore, 2∠PRQ=65×2=130∘