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This platform is brought to you by the intergeo project, funded under the eContent Plus programme of the European commission and by partners


The constraint symmetry_by_line( element e1, element e2 , line l) declares that e1 is the reflection of e2 about line l. There is a large variety of elements that can be reflected.

See also symmetry_by_point and symmetry_by_circle.


  1. symmetry_by_line example: source JSXGraph
  2. properties_of_ray example: source JSXGraph
  3. directed_line_segment example: source JSXGraph