Desargues's theorem
Teorema de Desargues
- Date
- 1639 (publicado en 1648) · confidence medium
- Place
- Paris, France
- Credited to
- Gérard Desargues
- Field
- Knowledge & symbols
What was discovered
Desargues established that two triangles are in axial perspective if and only if they are in central perspective: if the lines joining their corresponding vertices meet at a point, then the intersection points of their corresponding sides are collinear. The theorem is a basic coordinatisation principle of projective geometry.
Desargues never published the result himself; it appeared as an appendix to a treatise by his student Abraham Bosse in 1648, though Desargues had developed it years earlier in his work on conics.
What it led to
- The founding of projective geometry
- The distinction between 'Desarguesian' and 'non-Desarguesian' projective planes