Question

In the following figure, PQ and PR are tangents to the circle, with centre O. If ∠ QPR = 60° , calculate:

∠ QSR 

Answer 1

Now arc RQ subtends ∠QOR at the centre and ∠QSR at the remaining part of the circle.

`therefore angle "QSR" = 1/2 angle "QOR"`

`=> angle "QSR" = 1/2 xx 120^circ`

⇒ ∠QSR = 60°