Dynamic Geometry 1450: Ortholine, Steiner Line
The orthocenters of the four components triangles (BCE, ABF, ADE, CDF) of a complete quadrilateral ABCDEF lie on a line called Ortholine or Steiner Line.
Complete quadrilateral
Complete quadrilateral ABCDEF is the figure determined by four lines, no three of which are concurrent, and their six points of intersection A, B, D, C, E, and F.
Orthocenter
The orthocenter is the intersection of the three altitudes of a triangle.
Static Diagram of the Ortholine or Steiner Line
Step-by-step diagrams after exporting from GeoGebra
Poster of the Ortholine or Steiner Line using iPad Apps
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Classroom Resource:
Interactive step-by-step animation using GeoGebra
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