%0 Journal Article
%T On Poncelet's porism
%A Waldemar Cie lak
%A El bieta Szczygielska
%J Annales UMCS, Mathematica
%D 2010
%I 
%R 10.2478/v10062-010-0011-0
%X We consider circular annuli with Poncelet's porism property. We prove two identities which imply Chapple's, Steiner's and other formulas. All porisms can be expressed in the form in which elliptic functions are not used.
%K Porism
%K annulus
%K bicentric polygon
%U http://versita.metapress.com/content/yx6xp4707773gm01/?p=9103deacfc2242cb8d5ede9bf0cc3318&pi=2