MathDB

ASU 521 All Soviet Union MO 1990 concurrent circumcircles

Source:

August 14, 2019

circumcircleconcurrentgeometry

Problem Statement

ABCD

is a convex quadrilateral.

X

is a point on the side

AB. AC

and

DX

intersect at

Y

. Show that the circumcircles of

ABC, CDY

and

BDX

have a common point.