A Lambert quadrilateral, or Ibn al-Haytham–Lambert quadrilateral,[1] is a hyperbolic quadrilateral. It has a base, AB, two legs standing at right angles to it, AC and BD, and the summit, CD, meets one of the two legs at a right angle and the other leg at a non-obtuse angle. It is composed entirely of straight lines.
With perspective
The Lambert quadrilateral was first described in a proof of the parallel postulate given by Ibn al-Haytham (Alhacen) in the 11th century.[2] Johann Lambert later realized it in the 18th century while studying the Khayyam-Saccheri quadrilaterals.
Notes
- ^ Boris Abramovich Rozenfelʹd (1988), A History of Non-Euclidean Geometry: Evolution of the Concept of a Geometric Space, p. 65. Springer, ISBN 0387964584.
- ^ Smith, John D. (1992). "The Remarkable Ibn al-Haytham", The Mathematical Gazette 76 (475), p. 189-198.
References
- George E. Martin, The Foundations of Geometry and the Non-Euclidean Plane, Springer-Verlag, 1975
