DescriptionLexell's theorem in the hyperbolic plane (half-plane model).png
English: Lexell's theorem: triangles of constant area on fixed base AB have their free vertex C along a small circle through points antipodal to A and B. In the half-plane model of hyperbolic geometry, antipodal points are outside the hyperbolic plane.
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Lexell's theorem: triangles of constant area on fixed base AB have their free vertex C along a small circle through points antipodal to A and B. In the half-plane model of hyperbolic geometry, antipodal points are outside the hyperbolic plane.