Ptolemy circles and Ptolemy segments


In this paper we characterize Ptolemy circles and Ptolemy segments up to isometry. Moreover, we present an example of a metric sphere, which is Möbius equivalent but not homothetic to the standard metric sphere with its chordal metric.

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Correspondence to Thomas Foertsch.

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Foertsch, T., Schroeder, V. Ptolemy circles and Ptolemy segments. Arch. Math. 98, 571–581 (2012).

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  • Triangle Inequality
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