In fig, if line PQ and RS intersect at point T, such that ∠PRT=40∘ , ∠RPT=95∘ and ∠TSQ=75∘, find ∠SQT. [4 MARKS]
Concept: 2 Marks
Application: 2 Marks
In ΔPRT
⇒∠PTR+∠PRT+∠RPT=180∘ (since the sum of the angles of a triangle is 180∘)
⇒∠PTR+40∘+95∘=180∘
⇒∠PTR+135∘=180∘
⇒∠PTR=180∘−135∘
⇒∠PTR=45∘
⇒∠QTS=∠PTR=45∘ (Vertically Opposite angles)
In ΔTSQ
⇒∠QTS+∠TSQ+∠SQT=180∘ (since the sum of the angles of a triangle is 180∘)
⇒∠SQT+45∘+75∘=180∘
⇒∠SQT+120∘=180∘
⇒∠SQT=180∘−120∘
⇒∠SQT=60∘