Representation method of angle
First, use three uppercase English letters, for example: ∠AOC (the vertex is written in the middle, indicating that the angle is the angle between the ray OA and the line segment OC).
Second, it is represented by uppercase English letters, such as ∠O (indicating that the vertex of the angle is point O).
Third, use numbers, such as ∠ 1, ∠2, ∠3 (commonly used in math problems, used to mark abbreviations on graphs).
4. Use 1 Greek letter, for example: ∠ β.
Angles are measured in degrees, minutes and seconds. Divide a right angle into 180 equal parts, each part is an angle of one degree, and 1 degree is recorded as1; Divide the angle of 1 into 60 equal parts, each part is called a point angle, and it is recorded as1'; Divide the angle of 1' into 60 equal parts, each part is called the angle of 1 sec, and 1 sec is called 1 ". Angles are measured in hexadecimal, that is,
1 = 60′, 1′= 60″
Extended data
Angular unit
Angle is the unit for measuring angle, and the symbol is "0". A fillet is divided into 360 equal parts, and each part is defined as 1 degree (1 degree).
The value of 360 is adopted because it is easily divisible. In addition to 1 and ego, 360 has 2 1 real factors (2, 3, 4, 5, 6, 8, 9, 10, 12, 15,15.
In practical application, the angle of an integer is accurate enough. When more accurate angle values are needed, such as measuring the latitude and longitude of a star or the earth in astronomy, angles can be subdivided into angular minutes and angular seconds: 1 degree is 60 minutes (60'), and 1 degree is 60 seconds (60 "). For example, 40.1875 = 4011'15 ". In order to be more accurate, the angular seconds are expressed in decimals without adding units.
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