Original: Models of the hyperbolic plane There are four models commonly used for hyperbolic geometry : the Klein model , the Poincaré disc model , the Poincaré half-plane model , and the Lorentz model , or hyperboloid model .
Simplified: Models of the hyperbolic plane There are three models commonly used for hyperbolic geometry : the Klein model , the Poincaré disc model , and the Lorentz model , or hyperboloid model .