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We give a short proof of a Ptolemy-style result first discovered and provedby Jane McDougall. It may be viewed as a generalization to any even number ofpoints of the cubic relation connecting the six joint distances of four pointson a circle (whose quadratic relation is the famed Plucker relation, aliasPtolemy's theorem).  This article is in fond memory of Andrei Zelevinsky (1953-2013) who lovedPtolemy's theorem.

A Short Proof of a Ptolemy-Like Relation for an Even number of Points on a Circle Discovered by Jane McDougall