circumference

limit(°)

second(")

radian(rad)

right angle(rad)

points( ′)

milliradian(mrad)

gon( ′)

Angular unit conversion

The unit of angle conversion is degree, which is the unit used to measure the size of angle, and the symbol is °.

The angle of a circle is divided into 360 equal parts, each defined as 1 degree (1°).

The number 360 is used for the angle because it is easily divisible.

By definition, the number of radians in a cycle is 2πr/r=2π, and an angle of 360° =2π radians, so 1 radian is approximately 57.3°, or 57°17'44.806', 1° is π/180 radians, approximately 0.01745 radians, a circumferential angle is 2π radians, a straight angle (i.e., an angle of 180°) is π radians, and a right angle is π/2 radians.

In specific calculations, when angles are given in radians, they are usually written directly without radians. The most typical examples are trigonometric functions such as sin 8π, tan (3π/2).