MathDB

The extension of the bisector of angle

A

of triangle

ABC

intersects with the circumscribed circle of this triangle at point

W

. A straight line is drawn through

W

, which is parallel to side

AB

and intersects sides

BC

and

AC

, at points

N

and

K

, respectively. Prove that the line

AW

is tangent to the circumscribed circle of

\vartriangle CNW

.
(Sergey Yakovlev)

Problem Statement