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.
In Euclidean plane geometry, a rectangle is a quadrilateral with four right angles. It can also be defined as an equiangular quadrilateral, since equiangular means that all of its angles are equal (360Â°/4 = 90Â°). It can also be defined as a parallelogram containing a right angle. A rectangle with four sides of equal length is a square. The term oblong is occasionally used to refer to a non-square rectangle. A rectangle with vertices ABCD would be denoted as ABCD.