![Lesson 5.3 File](http://s1.studyres.com/store/data/003947133_1-c9e461dddd7251351840797732b6d33c-300x300.png)
The Postulates of Neutral Geometry Axiom 1 (The Set Postulate
... alternate interior angles, then they are parallel. Corollary 6.12 (Corresponding Angles Theorem). If two lines are cut by a transversal making a pair of congruent corresponding angles, then they are parallel. Corollary 6.13 (Consecutive Interior Angles Theorem). If two lines are cut by a transversal ...
... alternate interior angles, then they are parallel. Corollary 6.12 (Corresponding Angles Theorem). If two lines are cut by a transversal making a pair of congruent corresponding angles, then they are parallel. Corollary 6.13 (Consecutive Interior Angles Theorem). If two lines are cut by a transversal ...
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.