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\title{Ptolemy's Theorem}
\author{Lukas Bulwahn}
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\begin{abstract}

This entry provides an analytic proof to Ptolemy's Theorem using
polar form transformation and trigonometric identities.
In this formalization, we use ideas from John Harrison's HOL Light
formalization~\cite{Harrison} and the proof sketch on the Wikipedia entry of
Ptolemy's Theorem~\cite{wiki:PtolemysTheorem-2016}.
This theorem is the 95th theorem of the Top 100 Theorems list~\cite{Wiedijk}.

\end{abstract}

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