In an isosceles triangle ABC, with AB = AC, the bisectors of ∠B and ∠C intersect each other at O. Join A to O. Show that:
(i) OB = OC
(ii) AO bisects ∠A.
Given: In ∆ ABC, AD is the perpendicular bisector of BC.
To Prove: A ABC is an isosceles triangle in which AB = AC.
Proof: In ∆ ADB and ∆ADC,
∠ADB = ∠ADC | Each = 90° DB = DC
| ∵ AD is the perpendicular bisector of BC
AD = AD | Common
∴ ∆DB ≅ ∆ADC | By SAS Rule
∴ AB = AC | C.P.C.T.
∴ ∆ABC is an isosceles triangle in which AB = AC.