radian
英 ['re?d??n]
美['red??n]
- n. [數] 弧度
- n. (Radian)人名；(羅)拉迪安
英英釋意
- 1. the unit of plane angle adopted under the Systeme 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)