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
Enhanced Fujita scale damage descriptions given are those from the Fujita scale, which are more or less still accurate. However, for the actual EF scale in practice, damage indicators (the type of structure which has been damaged) are predominantly used in determining the tornado intensity. The EF scale currently has 28 damage indicators (DI), or types of structures and vegetation, each with a varying number of degrees of damage (DoD). Larger degrees of damage done to the damage indicators correspond to higher wind speeds. The links in the right column of the following table describe the degrees of damage for the damage indicators