Question

O is the centre of the circle, bo is the bisector of angle ABC. show that AB=AC..Please please urgent

Answer 1

This Forms two triangles which is ΔACO and ΔABO 

SO we have to prove these two triangles congruent to get our answer. 
So, 
CO = BO {Radii of same circle}
AO = AO {common side}
∠CAO = ∠BAO {Because it is bisected by Bisected by AO} 
Also, since AO = BO = CO the triangles are isosceles 
So ∠ACO = ∠ABO 
Therefore, Since 180 and two pairs of the Interior, are equal to add angle angle: 
∠AOC = ∠ABO 

Therefore ΔACO and ΔABO are congruent triangles by SAS Congruency Rule.
Hence , AC= AB by CPCT Corresponding Parts of Congruent Triangles(CPCT)

Hope It Helped :)