In the given figure, if AB = BC and ∠BAO=∠BCO=90∘, then prove that triangle ABO triangle CBO are congruent.
In △ABO and △CBO
(i) ∠BAO=∠CAO=90∘ ........ (given)
(ii) BO = BO .........(common side)
(iii) AB = BC........ (given) (1 Mark)
⇒△ABO≅△CBO ........ (RHS Postulate)
⇒ OA = OC.......(cpct)
⇒ ∠ABO=∠CBO=60∘ ........(cpct) (1 Mark)