n. the length of a line segment between the center and circumference of a circle or sphere
n. a straight line from the center to the perimeter of a circle (or from the center to the surface of a sphere)
n. a circular region whose area is indicated by the length of its radius
n. the outer and slightly shorter of the two bones of the human forearm
n. 半径, 范围, 辐射光线
[电] 半径
1. The radius of the circle is five centimeters.
这个圆的半径是五厘米。
2. To find the area of a circle, you need to know the radius.
要计算圆的面积，你需要知道半径。
3. The radius of the Earth is about 6,371 kilometers.
地球的半径大约是6371公里。