MathDB

2012 preRMO p14, angle chasing, incenter, circumcenter related

Source:

June 17, 2019

geometryincenterAngle Chasing

Problem Statement

O

and

I

are the circumcentre and incentre of

\vartriangle ABC

respectively. Suppose

O

lies in the interior of

\vartriangle ABC

and

I

lies on the circle passing through

B, O

, and

C

. What is the magnitude of

\angle B AC

in degrees?