Keywords: Relation5models.png en PoincarĂ© disk hemispherical and hyperboloid models are related by central projection from ˆ’1 Klein disk model is vertical projection from hemispheric model PoincarĂ© half-plane model here projected from the hemisphere model by rays from left end of PoincarĂ© disk model 2012-03-07 own assumed Selfstudier Models of the hyperbolic plane English text Projection |