Question

In triangle ABC, the sides AB and AC are produced to E and D respectively. If bisectors of angle CBE and angle BCD are BD and CO respectively,then prove that angle BOC=90 degree minus angle A divided by 2

Answer 1

In triangle ABC,
Angle a+b+c=180degrees
a+180-2x+180-2y=180degrees
(x+y)= angle+90
in triangle BOX
x+y+angle o =180degrees
Angle o =180-(x+y)
=180-angle a -90/2
AngleBOC= 90-Angle a/2