Degree (angle)
The degree is the unit of the plane angle, the symbol is "°". One corner is divided into 360 equal parts, each defined as 1 degree (1 °). The reason why 360 is used because it is easy to be divisible. 360 in addition to 1 and their own, there are 22 real factors (2,3,4,5,6,8,10,12,15,18,20,24,30,36,45,60,72,90,120 , 180), so many special angle angles are integers. In practical applications, the integer angle has been accurate enough. When you need a more accurate angle value, such as astronomy in the measurement of the stars or Earth's longitude and latitude, in addition to the available decimal, but also the angle can be divided into angle and angle seconds: 1 degree for 60 points (60 '), 1 For 60 seconds (60 "), for example 40.1875 ° = 40 ° 11'15". To be more accurate, then use the decimal number that seconds, no longer add units. ...