John Casey (born 12 May 1820 at Kilkenny, Ireland, died 3 January 1891 at Dublin) was a respected Irish geometer. He is most famous for Casey's theorem on a circle that is tangent to four other circles, an extension of the problem of Apollonius. However, he contributed several novel proofs and perspectives on Euclidean geometry. He and Émile Lemoine are considered to be the co-founders of the modern geometry of the circle and the triangle.

Contents 1 Major works 2 See also 3 References 4 External links

[edit] Major works

• On Cubic Transformations (Dublin, 1880)
• A Sequel to the First Six Books of the Elements of Euclid (Dublin, 1881)
• The First Six Books of the Elements of Euclid (Dublin, 1882)
• Treatise on the Analytic Geometry of the Point, Line, Circle and Conic Sections (Dublin, 1885)
• Treatise on Elementary Trigonometry (Dublin, 1886)
• Treatise on Plane Trigonometry containing an account of the Hyperbolic Functions (Dublin, 1888)
• Treatise on Spherical Geometry (Dublin, 1889).

[edit] See also

• 1913 Catholic Encyclopedia article on John Casey

[edit] References

• Irish Monthly (1891), XIX, 106, 152
• Proc. Royal Society (1891), XLIX, 30, p. xxiv.

[edit] External links

• MacTutor History of Mathematics