Editing Reuleaux triangle (section)

=== Mapmaking ===
{{main | octant projection }}
Another early application of the Reuleaux triangle, [[da Vinci's world map]] from circa 1514, was a [[world map]] in which the spherical surface of the earth was divided into eight octants, each flattened into the shape of a Reuleaux triangle.<ref name="snyder">{{citation|title=Flattening the Earth: Two Thousand Years of Map Projections|first=John P.|last=Snyder|publisher=University of Chicago Press|year=1997|isbn=978-0-226-76747-5|page=40|url=https://books.google.com/books?id=0UzjTJ4w9yEC&pg=PA40}}.</ref><ref>{{citation
 | last = Keuning | first = Johannes
 | date = January 1955
 | doi = 10.1080/03085695508592085
 | issue = 1
 | journal = [[Imago Mundi]]
 | jstor = 1150090
 | pages = 1–24
 | title = The history of geographical map projections until 1600
 | volume = 12}}.</ref><ref name="dee">{{citation
 | last = Bower | first = David I.
 | date = February 2012
 | doi = 10.1179/1743277411y.0000000015
 | issue = 1
 | journal = [[The Cartographic Journal]]
 | pages = 55–61
 | title = The unusual projection for one of John Dee's maps of 1580
 | url = http://dibower.co.uk/data/documents/Dee-projn-paper.pdf
 | volume = 49| bibcode = 2012CartJ..49...55B
 | s2cid = 129873912
 }}.</ref>
[[File:Leonardo da Vinci’s Mappamundi.jpg|thumb|center|upright=2|Leonardo [[da Vinci's world map]] in eight Reuleaux-triangle quadrants]]

Similar maps also based on the Reuleaux triangle were published by [[Oronce Finé]] in 1551 and by [[John Dee]] in 1580.<ref name="dee" />