Abstract
An n-sided hyperbolic polygon of type (ϵ, n) is a hyperbolic polygon with ordered interior angles
$\begin{array}{}
\frac{\pi}{2}
\end{array} $ + ϵ, θ1, θ2, …, θn−2,
$\begin{array}{}
\frac{\pi}{2}
\end{array} $ − ϵ, where 0 < ϵ <
$\begin{array}{}
\frac{\pi}{2}
\end{array} $ and 0 < θi < π satisfying
$$\begin{array}{}
\displaystyle \sum_{i = 1}^{n-2} \theta_{i}+\Big(\frac{\pi}{2}+\epsilon\Big)+\Big(\frac{\pi}{2}-\epsilon\Big) \lt (n-2)\pi
\end{array} $$
and θi + θi+1 ≠ π (1 ≤ i ≤ n − 3), θ1 + (
$\begin{array}{}
\frac{\pi}{2}
\end{array} $ + ϵ) ≠ π, θn−2 + (
$\begin{array}{}
\frac{\pi}{2}
\end{array} $ − ϵ) ≠ π. In this paper, we present a new characterization of Möbius transformations by using n-sided hyperbolic polygons of type (ϵ, n). Our proofs are based on a geometric approach.