an SI unit of plane angle; the angle between two radii of a circle that cut off on the circumference an arc equal in length to the radius. 1 radian is equivalent to 57.296 degrees and π/2 radians equals a right angle
Symbol: rad
Word origin
C19: from radius
radian in American English
(ˈreɪdiən)
noun
the basic unit of plane angle in the SI system, equal to 57°, 17′, 44.8″ (57.29578°, the angleformed at the center of a circle by two radii cutting off an arc whose length is equal to the radius of the circle): one degree equals0.017454 radian and 360 degrees equals 2π radians
abbrev. rad
Word origin
< radius
radian in Electrical Engineering
(reɪdiən) or rad
Word forms: (regular plural) radians
noun
(Electrical engineering: General)
The radian is the plane angle between two radii of a circle that cut off on the circumferencean arc equal in length to the radius.
The radian is the standard unit of angular measure, used in many areas of mathematics.
Since radians are a unit-less measurement the normalized angular frequency is sometimes referredto as inverse samples.
The radian is the plane angle between two radii of a circle that cut off on the circumferencean arc equal in length to the radius.