Question

In triangle ABC , the bisectors of angle ABC and angle BCA intersect at O. Prove that angle BOC= 90 degree + angle A /2.

Answer 1

i think u can understand this

Answer 2

a+b+c=180
multiplying with half
a/2+b/2+c/2=90
a/2+obc+ocb=90
obc+ocb=90-a/2
taking triangle obc
obc+ocb+boc=180
90-a/2+boc=180
boc=90+a/2