Y by
In a convex quadrilateral
we draw the bisectors
,
,
,
of external angles
,
,
,
respectively. The intersection points of the lines
and
,
and
,
and
,
and
are designated by
,
,
,
. It is known that
perpendiculars drawn from
on
, from
om
, from
on
intersect at one point. Prove that the quadrilateral
is cyclic.




























