国际单位制采用的平面角单位；长度等于半径的弧所对的圆心角。

国际单位制采用的平面角单位；长度等于半径的弧所对的圆心角。的英文翻译

基本释义

• the unit of plane angle adopted under the System International d'Unites; equal to the angle at the center of a circle subtended by an arc equal in length to the radius (approximately 57.295 degrees).