Prove that a diameter of a circle which bisects a chord of the circle also bisects the angle subtended by the chord at the centre of the circle.
Given that,
PQ is a diameter of circle which bisects chord AB to C
To prove: PQ bisects ∠AOB
Proof: In ,
OA = OB (Radius of circle)
OC = OC (Common)
AC = BC (Given)
Then,
(By SSS congruence rule)
∠AOC = ∠BOC (By c.p.c.t)
Hence, PQ bisects ∠AOB.