The Online Books Page

Triangle

See also what's at Wikipedia, your library, or elsewhere.

• Geometry, Plane

• Circles of the triangle

• La Recente Geometria del Triangolo (in Italian; Città di Castello: S. Lapi, 1900), by Cristoforo Alasia
  • multiple formats at Google; US access only
  • page images at HathiTrust; US access only

Items below (if any) are from related and broader terms.

• Chapters on the Modern Geometry of the Point, Line, and Circle, by Richard Townsend
  • volume 1: page images at Cornell
  • volume 2: page images at Cornell
• Euclid's Book on Divisions of Figures, by Raymond Clare Archibald (page images at Cornell)
• A New Analysis of Plane Geometry, Finite and Differential, with Numerous Examples, by A. W. H. Thompson (page images at Cornell)
• Plane Geometry (second edition, 1913), by George Wentworth and David Eugene Smith, contrib. by G. A. Wentworth (PDF at djm.cc)

• The Analytical Geometry of the Conic Sections (London: A. and C. Black, 1908), by E. H. Askwith (page images at HathiTrust)
• Conic Sections Treated Geometrically, by W. H. Besant (page images at Cornell)
• An Introduction to the Ancient and Modern Geometry of Conics, by Charles Taylor (page images at Cornell)
• Researches on Curves of the Second Order, by George Whitehead Hearn (page images at Cornell)
• A Course of Pure Geometry: Containing a Complete Geometrical Treatment of the Properties of the Conic Sections (Cambridge: At the University Press, 1917), by E. H. Askwith (multiple formats at archive.org)
• A Treatise on Plane Co-ordinate Geometry As Applied to the Straight Line and the Conic Sections (1881 edition), by I. Todhunter (page images at Cornell)
• Brouillon Project d'une Atteinte aux Evenemens des Rencontres du Cone avec un Plan, par L,S,G,D,L (in French; 1639), by Gérard Desargues
  • page images at Gallica
  • black and white facsimile with slightly different page order: page images at Gallica
• A Treatise on Some New Geometrical Methods, by James Booth
  • volume 1: page images at Cornell
  • volume 2: page images at Cornell

• Lectures on the Differential Geometry of Curves and Surfaces, by Andrew Russell Forsyth (page images at Cornell)
• The Elements of the Differential Calculus, by J. R. Young (page images at Cornell)

• Comparison Geometry (1997), ed. by Karsten Grove and Peter Petersen (PDF files with commentary at msri.org)

• Thèses Presentées a la Faculté des Sciences de Paris, Pour Obtenier le Grade de Docteur ès Sciences Mathématiques: Sur le Cercle Considéré Comme Élément Générateur de L'espace; Propositions Données par la Faculté (dissertation in French; Paris: Gauthier-Villars et fils, 1889), by E. Cosserat (Javascript-dependent page images in France)

• Algebraic Curves: An Introduction to Algebraic Geometry (electronic edition, 2008), by William Fulton (PDF with commentary at Michigan)

• Elementary Number Theory: Primes, Congruences, and Secrets (free online edition, 2011), by William A. Stein (PDF with commentary at wstein.org)

• The Eightfold Way: The Beauty of Klein's Quartic Curve (1999), ed. by Silvio Levy (PDF files with commentary at msri.org)

• A Treatise on the Cycloid and All Forms of Cycloid Curves, by Richard A. Proctor (page images at Cornell)

• Elements of Quaternions, by Arthur Sherburne Hardy (page images at Cornell)
• Lectures on Quaternions, by William Rowan Hamilton (page images at Cornell)
• A Manual of Quaternions, by Charles Jasper Joly (page images at Cornell)
• The Outlines of Quaternions, by H. W. L. Hime (page images at Cornell)
• A Primer of Quaternions, by Arthur S. Hathaway
  • Gutenberg PDF and zipped LaTeX
  • page images at Cornell
• Quaternions as the Result of Algebraic Operations, by Arthur Latham Baker (page images at Cornell)
• Utility of Quaternions in Physics, by Alex. McAulay (page images at Cornell)
• Vector Analysis and Quaternions, by Alexander Macfarlane (page images at Cornell)
• Vector and Tensor Analysis (New York: J. Wiley and Sons; London: Chapman and Hall, c1947), by Louis Brand (page images at HathiTrust)

• Bibliography of Quaternions and Allied Systems of Mathematics, by Alexander Macfarlane (page images at Cornell)

• Grassmann's Space Analysis, by E. W. Hyde (page images at Cornell)

• Notes on Roulettes and Glissettes, by W. H. Besant (page images at Cornell)

• Determination of Azimuth Angle at Burnout for Placing a Satellite Over a Selected Earth Position (NASA Technical Note D-233; 1960), by T. H. Skopinski and Katherine G. Johnson (page images at HathiTrust)

• New Moons: Towing Asteroids into Earth Orbits for Exploration and Exploitation: Transcripts of the Presentations at the Special Session of the Eighth Lunar Science Conference, 16 March 1977, Johnson Space Center, Houston, Texas (Houston: Lunar and Planetary Institute, 1977), ed. by David R. Criswell (PDF at USRA Houston Repository)

• Determination of Azimuth Angle at Burnout for Placing a Satellite Over a Selected Earth Position (NASA Technical Note D-233; 1960), by T. H. Skopinski and Katherine G. Johnson (page images at HathiTrust)

• Survey of Characteristic Velocity Requirements for Two-Impulse Transfers Between Circular and Coplanar Exterior Elliptical Orbit With Exposition of Local and Overall Optimum Solutions (NASA Technical Note D-600; Washington: National Aernoautics and Space Administration, 1961), by Robert Silber (page images at HathiTrust)

• Byrne's Euclid: The First Six Books of the Elements of Euclid, With Coloured Diagrams and Symbols, by Euclid, ed. by Oliver Byrne and Nicholas Rougeux (JavaScript-dependent illustrated HTML at c82.net)
• The First Six Books of the Elements of Euclid, and Propositions I.-XXI. of Book XI., and an Appendix on the Cylinder, Sphere, Cone, Etc., With Copious Annotations and Numerous Exercises (Dublin: Hodges, Figgis and Co., 1885), by Euclid and John Casey (page images at Cornell)
• The Story of Euclid (London: George Newnes, 1902), by William Barrett Frankland (PDF at djm.cc)

• A Key to the Exercises in the First Six Books of Casey's Elements of Euclid, by Joseph Casey (page images at Cornell)

• Briot and Bouquet's Elements of Analytical Geometry of Two Dimensions, by M. Briot, trans. by James Harrington Boyd (page images at Cornell)
• A Course of Pure Geometry: Containing a Complete Geometrical Treatment of the Properties of the Conic Sections (Cambridge: At the University Press, 1917), by E. H. Askwith (multiple formats at archive.org)
• An Introduction to Algebraical Geometry, by A. Clement Jones (page images at Cornell)
• Solutions to Problems Contained in A Treatise on Plane Co-ordinate Geometry, by I. Todhunter (page images at Cornell)
• A Treatise on Plane Co-ordinate Geometry As Applied to the Straight Line and the Conic Sections (1881 edition), by I. Todhunter (page images at Cornell)
• The Analytical Geometry of the Conic Sections (London: A. and C. Black, 1908), by E. H. Askwith (page images at HathiTrust)

More items available under broader and related terms at left.