There are several causes of dry mouth: 1  Effects of certain medications. 2  Side effects of certain medical conditions, for example SjÃ¶gren's syndrome, and infections. 3  Side effect of certain medical treatments.  Nerve 1  damage. Dehydration.  Surgical removal of the salivary 1  glands. Lifestyle.
Euclidean geometry. Euclidean geometry is a mathematical system attributed to the Alexandrian Greek mathematician Euclid, which he described in his textbook on geometry: the Elements. Euclid's method consists in assuming a small set of intuitively appealing axioms, and deducing many other propositions (theorems) from these.
The term non-Euclidean sounds very fancy, but it really just means any type of geometry that's not Euclideanâi.e., that doesnât exist in a flat world. A non-Euclidean geometry is a rethinking and redescription of the properties of things like points, lines, and other shapes in a non-flat world. Spherical geometryâwhich is sort of plane geometry warped onto the surface of a sphereâis one example of a non-Euclidean geometry. Non-Euclidean Geometry in the Real World