radian
[rā′dē ən]
noun
the basic unit of plane angle in the SI system, equal to 57°, 17′, 44.8″ (57.29578°, the angle formed 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 equals 0.017454 radian and 360 degrees equals 2π radians: abbrev. rad
Origin: from radius
Used by arrangement with John Wiley & Sons, Inc.
noun Abbr. rad
A unit of angular measure equal to the angle subtended at the center of a circle by an arc equal in length to the radius of the circle, approximately 57°17:44.6″. See Table at measurement.
Origin: radi(us) + -an1.
radian - Computer Definition
From the Latin radius. A unit of plane angular measurement equivalent to the angle between two radii that enclose a section of a circle's circumference (arc) equal in length to the length of a radius.There are 2 radians in a circle. See also frequency and radius.
Used by arrangement with John Wiley & Sons, Inc.
radian - Medical Definition
noun Abbr. rad
A unit of angular measure equal to the angle subtended at the center of a circle by an arc equal in length to the radius of the circle.
radian - Science Definition
A supplementary unit of the International System used in angular measure. One radian is equal to the angle subtended at the center of a circle by an arc equal in length to the radius of the circle, approximately 57°17:44.6″.
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