Bisector AD of ∠BAC of ΔABC passes through the centre O of the circumcircle of ΔABC. Prove that AB = AC. [2 MARKS]
Concept: 1 Mark
Application: 1 Mark
Bisector AD of ∠BAC of ΔABC passes through the centre O of the circumcircle of ΔABC .
To prove that AB = AC
Construction: Draw OP⊥AB and OQ⊥AC
Proof :
In ΔAPO and ΔAQO
∠OPA=∠OQA=90∘ (by construction)
∠OAP=∠OAQ Given
OA=OA Common
∴ΔAPO≅ΔAQO by AAS
∴OP=OQ by C.P.C.T
∴AB=AC Two chords equidistant from the center are equal.
Hence proved.