[" If "" If the bisectors of angles "/_ABC" and "/_ACB" of a triangle "ABC" meet "],[/_BOC=90^(@)+(1)/(2)/_A]

The sides AB and AC of ABC are product to P and Q respectively.the bisectors of exterior angles at B and C of ABC meet at O( fig..19) prove that /_BOC=90^(@)-(1)/(2)/_A

The sides AB and AC of a Delta ABC are produced to P and Q respectively.If the bisectors of /_PBC and /_QCB ; Then /_BOC=90^(@)-(1)/(2)/_A

In ABC, if /_B=60^(@),/_C=80^(@) and the bisectors of angles /_ABC and /_ACB meet at a point O, then find the measure of /_BOC .

If the bisector of the angle A of triangle ABC meets BC in D, prove that a=(b+c)[1-([AD]^(2))/(bc)]^((1)/(2))

ANGLES The three angles -BAC-ABC and -ACB are called the angles of Delta ABC .

The bisectors of the angles ABC and BCA of a triangle ABC meet in a point 0. What is the angle at O facing the side BC ?