Degree
A '''degree''' (in Latin ''gradus'', meaning "a step") is a term with multiple meanings. Most commonly, it refers to a unit of angular or temperature measurement, a mathematical concept, or an academic qualification awarded upon completing a course of study. In measurement, a degree is one 360th of a circle (angular degree) or a unit of temperature interval on scales such as Celsius or Fahrenheit.[1] In mathematics, the degree can denote the highest power of a variable in a polynomial or the number of connections at a point in a graph.[1] An academic degree signifies achievement in higher education, with types including associate, bachelor's, master's, and doctoral levels. Detailed information on academic degrees is covered in the dedicated section below. The term also appears in other contexts, such as science, law, and named entities. For a full list of uses, see the article sections.Units of Measurement
Angular Degree
The angular degree is a unit of plane angle measurement, defined as one three-hundred-sixtieth (1/360) of a complete rotation or full circle. This convention traces its roots to ancient Babylonian astronomy, where the approximate 360-day solar year inspired the division of the ecliptic path into 360 equal parts for tracking celestial movements. The system emerged in Mesopotamia during the Old Babylonian period, around 2000 BCE, as part of early sexagesimal (base-60) mathematics used for astronomical calculations.[2][3][4] The degree was formalized and integrated into Western mathematics through Greek adoption in the Hellenistic era. Hipparchus of Nicaea, a prominent astronomer in the 2nd century BCE, borrowed the 360-degree circle division from Babylonian sources and applied it systematically in his star catalog and trigonometric tables, marking a key advancement in angular measurement. The symbol for the degree, °, appeared in print during the Renaissance, with early instances traceable to French mathematician Jacques Pelletier du Mans in 1569, evolving from a superscript zero to denote fractional parts of circles. This notation is standard today, as in expressing a right angle as 90°.[5][6][7] For greater precision, the degree is subdivided using the sexagesimal system: one degree equals 60 arcminutes (denoted '), and one arcminute equals 60 arcseconds (denoted "). Thus, the equivalency is expressed as$1^\circ = 60' = 3600''.
This subdivision, inherited from Babylonian practices, allows measurements down to fractions of a degree, essential for fine angular resolutions. In applications, angular degrees are fundamental in astronomy for quantifying stellar separations and object sizes, such as the Moon's apparent diameter of about 0.5°; in land surveying, they define bearings and azimuths for mapping terrain with high accuracy; and in navigation, they specify compass directions (e.g., a heading of 45° northeast) or celestial sights for determining position at sea.[8][9][10][11] The angular degree relates to the radian, the International System of Units (SI) derived unit for plane angles, via the conversion formula
\theta_{\text{radians}} = \theta_{\text{degrees}} \times \frac{\pi}{180}.
This stems from the full circle equaling $2\pi radians or 360°, enabling seamless transitions in scientific computations; for instance, \pi radians corresponds exactly to 180°. While degrees remain prevalent in practical fields like navigation and surveying, radians are preferred in advanced physics and calculus for their natural alignment with circular arc lengths.[12]