![2.1 Use Inductive Reasoning](http://s1.studyres.com/store/data/000637861_1-46050094cf220157f24d09e1c5ab283e-300x300.png)
Hyperbolic Constructions using the Poincare Disk Model
... around, the center may disappear. Just construct a new intersection and a new circle so that when one disappears, the other reappears). Does the circumcenter always exist in the hyperbolic model? d. In Euclidean Geometry, the Centroid, Circumcenter and ...
... around, the center may disappear. Just construct a new intersection and a new circle so that when one disappears, the other reappears). Does the circumcenter always exist in the hyperbolic model? d. In Euclidean Geometry, the Centroid, Circumcenter and ...
3-manifold
![](https://commons.wikimedia.org/wiki/Special:FilePath/3-Manifold_3-Torus.png?width=300)
In mathematics, a 3-manifold is a space that locally looks like Euclidean 3-dimensional space. Intuitively, a 3-manifold can be thought of as a possible shape of the universe. Just like a sphere looks like a plane to a small enough observer, all 3-manifolds look like our universe does to a small enough observer. This is made more precise in the definition below.