Q.

In the given figure, PQ is tangent to a circle at O and BAQ=30°, show that BP = BQ.


Ans.

BQP=BAQ  (s in alternate segment are equal)

BQP=30°  ...(i) (∵ BAQ=30° given)

As AB is a diameter, AQB is a Semicircle.

AQB=90°  (angle in semicircle =90°)

From figure, AQP=AQB+BQP

AQP=90°+30°=120°

In AQP, QPA+BAQ+AQP=180°

QPA+30°+120°=180°

QPA=180°-(30°+120°)

QPA=30°  ...(ii)

From (i) and (ii) we get

BQP=QPB=30°

Therefore, QB = BP