Analysis:

In mathematics, it is represented by one apostrophe, and seconds are represented by two apostrophes.

brief introduction

The value of 360 is adopted because it is easily divisible. 360 Besides 1 and ego, there are 22 real factors (2, 3, 4, 5, 6, 8, 9, 10, 12, 15, 18, 20, 24.

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.