Ideal triangle

Three ideal triangles in the Poincaré disk model creating an ideal pentagon
Two ideal triangles in the Poincaré half-plane model

In hyperbolic geometry an ideal triangle is a hyperbolic triangle whose three vertices all are ideal points. Ideal triangles are also sometimes called triply asymptotic triangles or trebly asymptotic triangles. The vertices are sometimes called ideal vertices. All ideal triangles are congruent.