Prove that orthocenters of the four
components triangles (BCE, CDF, ABF, ADE) of a complete quadrilateral ABCDEF lie on a line called Ortholine, Steiner
line, Orthocentric line. See also:
Artwork
of Problem
1169,
Adobe Spark. Reference: David Wells. Curious and
Interesting Geometry, Penguin Books, 1991.
