Angle ‒ Size

Circular arc The value of a circular arc for an angle AVB is equal to the length of the arc ABAB, which is the intersection of the angle AVB with a circle centered at point V and with a radius of 1. The unit for measuring a circular arc is called the radian (represented by the symbol "rad"). A radian is the principal unit for measuring plane angles and is classified as a derived unit in the International System of Units (SI). Radians are primarily used in technical fields such as physics and electrical engineering. However, angles are more commonly measured in degrees for general use. Degree of arc The degree of arc originated from the geometry of an equilateral triangle, which was subdivided into 60 parts. This is why the system is called the "sexagesimal system". A full angle contains 360 degrees, and the unit of measurement is 1 degree, denoted by "º". The following relationship applies between degrees and radians: 1º = π / 180 rad An angular degree is divided into 60 angular minutes (1º = 60') An angular minute is further divided into 60 angular seconds (1' = 60"), i.e. 1º = 3600" Radians and degrees are the two most commonly used units for measuring angles. While other angular units are occasionally used in specialized fields, they are not commonly encountered in general practice.