Editing Involute (section)

== Involute and evolute ==
The [[evolute]] of a given curve <math>c_0</math> consists of the curvature centers of <math>c_0</math>. Between involutes and evolutes the following statement holds:
<ref>K. Burg, H. Haf, F. Wille, A. Meister: ''Vektoranalysis: Höhere Mathematik für Ingenieure, Naturwissenschaftler und ...'', Springer-Verlag, 2012,{{ISBN|3834883468}}, S. 30.</ref><ref>R. Courant:''Vorlesungen über Differential- und Integralrechnung, 1. Band'', Springer-Verlag, 1955, S. 267.</ref>
:''A curve is the evolute of any of its involutes.''
{{Gallery
|title= Involute and evolute
|width=160 | height=170
|align=center
|File:Involute.gif 
 |alt2=Involute of a catenary
 |Tractrix (red) as an involute of a catenary
|File:Evolute2.gif 
 |alt3=Evolute of a tractrix
 |The evolute of a tractrix is a catenary
}}