Step angle set
The step angle theorem is a mathematical theorem . It says: If two parallel straight lines a and b are intersected by a third straight line c, the step angles are the same.
The step angle theorem is reversible, ie the following applies: If two straight lines a and b are intersected by a third straight line c and the step angles are equal, then a and b are parallel.
literature
- Hans Schupp: Elementary Geometry . Schöningh, Hannover 1977, ISBN 3-506-99189-2 . , P. 37
- Hendrik Kasten, Denis Vogel: Fundamentals of plane geometry . Springer 2018, pp. 78–81