If a quadrilateral ABCD, the bisector of `angleC & angleD` intersect at O.
Prove that `angleCOD=(1)/(2)(angleA+angleB)`

In DeltaABC , the bisectors of angleB and angleC intersect each other at O. Prove that. angleBOC=90^(@)+(1)/(2)angleA .

In quadrilateral ABCD, the bisectors of /_A and /_B intersect at E. Prove that, /_C+ /_D = 2/_ AEB.

angleACD is an exterior angle of DeltaABC and he bisector of angleA intersects BC at E. Prove that, angleABC+angleACD=2angleAEC .

In triangle ABC, AB = AC and the bisector of angle A lt intersects BC at D. Prove that, ( 1 ) triangle ADB = triangle ADC ( 2 ) angle ABC = angle ACB

In triangleABC the bisectors of angleB and angleC intersect at I if angleA=70^(@) then angle BIC=…………..

In a parallelogram ABCD, the bisectors of the consecutive angles angleA and angleB intersect at P. Show that angleAPB=90^(@) .

In triangle ABC, the bisectors of angle B and angle C intersect at I. A line drawn through I and parallel to BC intersects AB at P and AC at Q. Prove that PQ = BP + CQ.

In cyclic quadrilateral ABCD. Diagonals AC and BD intersect at P. If angle DBC = 70^(@) and angle BAC = 30^(@) , find angle BCD.

In the adjacent figure the sides AB and AC of Delta ABC are produced to points E and D respectively. If bisectors BO and CO of angleCBE and angleBCD respectively meet at point O, then prove that angleBOC = 90^(@)-(1)/(2) angleBAC .

In parallelogram ABCD, the bisectors of /_A and /_B intersect at M. If /_A = 80^(@) , then /_AMB=…….