Spherical geometry other geometric concepts are defined as in plane geometry, but with straight lines replaced by great circles. Thus, in spherical geometry, angles are defined between great circles, resulting in a spherical trigonometry that differs from ordinary trigonometry in many respects; for example, the sum of the interior angles of a triangle exceeds 180 degrees. Spherical geometry is "not" elliptic geometry, but is rather a "subset" of elliptic geometry. For example, it shares with that geometry the property that a line has no parallels through a given point. Contrast this with Euclidean geometry, in which a line has one parallel through
ILR scale are able to perform most basic functions using the language; this includes buying goods, reading the time, ordering simple meals and asking for minimal directions Limited working proficiency is rated 2 on the scale. A person at this level is described as follows: Professional working proficiency is rated 3 on the scale. Level 3 is what is usually used to measure how many people in the world know a given language. A person at this level is described as follows: Individuals classified at level 3 are able to use the language as part of normal professional duties and can reliably