Angle unit points, display the query job help network. The apostrophe in mathematical coordinates indicates the unit minute of an angle, for example, 29 degrees and 30 minutes, which means 29 degrees and 30 minutes. Angle is a mathematical concept, which can describe the size of angle, that is, the amount that must be rotated when any one of two intersecting lines overlaps with another intersecting line. In international applications, the angle of an integer is accurate enough, and sometimes more accurate measurement is needed, such as astronomy or the latitude and longitude of the earth. In addition to expressing degrees in decimals, degrees can be subdivided into minutes and seconds.