Two equal circles passes through the centres of each other and intersect each other at A and B . A line passes through point A intersecting the two circles at points C and D . How can I prove that the triangle formed by the points B , C and D is equilateral ?
O and I are the circumcenter and incenter of triangle ABC respectively . O lies in the interior of ABC and I lies on the circle passing through B , O and C . what is the magnitude of angle BAC ?