An early instrument for measuring altitude of celestial bodies, consisting of a90= graduated arc with a movable radius for measuring angles. 象限仪用来测量天体纬度的一种早期工具，由一个有90度刻度的圆弧和一个用来测量角度的可移动的半径构成
Every family within a radius of25 miles of the city center. 住在离城中心半径25英里的范围内的家庭
Moving or directed along a radius. 沿着或向着半径移动的
The police searched all the fields and woods within a radius of two miles. 警察搜查了半径两英里范围内所有的田野和森林。
The radius of a circle described by a crank, cam, or similar machine part. （曲轴的）半径曲柄、凸轮或类似机器部件形成的圆的半径
