Circle of latitude can be calculated by a common sine or cosine function. The 60th parallel north or south is half as long as the Equator (disregarding Earth's minor flattening by 0.3%). A circle of latitude is perpendicular to all meridians. The latitude of the circle is approximately the angle between the Equator and the circle, with the angle's vertex at Earth's centre. The equator is at 0°, and the North Pole and South Pole are at 90° north and 90° south, respectively. The Equator is the longest circle of latitude and is the only circle of latitude which also is a great
Dell Latitude Latitude line generally retains identical components throughout its production. This design is intended to simplify maintenance and support tasks for large corporations, allowing components to be easily swapped between models. The lines of Dell Latitude personal computers are currently in the "E" series, which is the successor to the popular Latitude D, C, and X series. The Latitudes from the early 1990s up until the C*00 lines weren't in a set "series", instead going under the models CP and XP with modifiers at the end, e.g.: XPi, CP M233. In the past, the "mainstream" line was the 6 series, being