Casey's Theorem gives a condition, stated in terms of the lengths of common tangent lines between pairs of circles, for four circles to all be tangent to a single fifth circle or line. Named for John Casey, it generalizes Ptolemy's Theorem, which is recovered as the special case where each of the four circles shrinks to a point.
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StatementAlso known as the generalized Ptolemy's theorem, a theorem in Euclidean geometry named after the Irish mathematician John Casey. 1 Classification
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Source Casey's theorem, Wikipedia
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Source John Casey (mathematician) (Wikipedia)
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Source Casey's theorem, Wikipedia
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1. Casey's theorem, Wikipedia
Lead paragraph
Casey's theorem, also known as the generalized Ptolemy's theorem, is a theorem in Euclidean geometry named after the Irish mathematician John Casey.
Proved By: John Casey, Lead sentence
In mathematics, Casey's theorem, also known as the generalized Ptolemy's theorem, is a theorem in Euclidean geometry named after the Irish mathematician John Casey.
In Branch: Geometry, Lead sentence
he generalized Ptolemy's theorem, is a theorem in Euclidean geometry named after the Irish mathematician John Casey.
View the SourceJohn Casey (mathematician) (Wikipedia)
Principal Result Of: John Casey, LeadQuote, Principal Result Of: John Casey, Lead
He is most famous for Casey's theorem on a circle that is tangent to four other circles
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