IMO Shortlist 1966 problem 63
Avg:
Avg:
Let
be a triangle, and let
,
,
be three points in the interiors of the sides
,
,
of this triangle. Prove that the area of at least one of the three triangles
,
,
is less than or equal to one quarter of the area of triangle
.
Alternative formulation: Let
be a triangle, and let
,
,
be three points on the segments
,
,
, respectively. Prove that
,
where the abbreviation
denotes the (non-directed) area of an arbitrary triangle
.











Alternative formulation: Let








where the abbreviation


Izvor: Međunarodna matematička olimpijada, shortlist 1966