In the given figure, PQ is a chord of a circle with centre O and PT is a tangent. If ∠ QPT = 60o, find ∠ PRQ.
Given, PQ is a chord of a circle with center O. Also, ∠QPT = 60°.
let x be the point on the tangent PT.
Now, ∠QPT + ∠QPX = 180° [Linear pair]
⇒ ∠QPX = 180° - ∠QPT = 180° - 60° = 120°
Again, ∠QPX = ∠PRQ [Alternate segment theorem]
⇒ ∠PRQ = 120°