Melissa Baker and Robert C. Powers, A stronger triangle inequality
for neutral geometry,
Forum Geometricorum, 7 (2007) 25--29.
Abstract: Bailey and Bannister [College Math. Journal, 28 (1997)
182--186] proved that a stronger triangle inequality holds in the Euclidean
plane for all triangles having largest angle less than arctan(24/7)
(approximately 74 degrees). We use hyperbolic trigonometry to show
that a stronger triangle inequality holds in the hyperbolic plane for all
triangles having largest angle less than or equal to 65.87 degrees.
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