名詞 radius:

1. the length of a line segment between the center and circumference of a circle or sphere
   同義詞：r
2. a straight line from the center to the perimeter of a circle (or from the center to the surface of a sphere)
3. a circular region whose area is indicated by the length of its radius
4. the outer and slightly shorter of the two bones of the human forearm
5. support consisting of a radial member of a wheel joining the hub to the rim
   同義詞：spoke, wheel spoke

1. The radius of a circle described by a crank, cam, or similar machine part.
   (曲軸的)半徑曲柄、凸輪或類似機(jī)器部件形成的圓的半徑
2. We can compute the circular area with radius.
   我們能用半徑計(jì)算出圓的面積。
3. The police searched all the woods within a six-mile radius.
   警察搜索了在周圍六英里以內(nèi)的樹林各處。

ra.di.us

n.（名詞）
【復(fù)數(shù)】 ra.di.i[-dô-o.] 或 ra.di.us.es
Abbr. R,r,rad.Mathematics
縮寫 R,r,rad.【數(shù)學(xué)】
A line segment that joins the center of a circle with any point on its circumference.
圓半徑：將圓心與圓周上任一連接起來的線段
A line segment that joins the center of a sphere with any point on its surface.
球半徑：將心與球面上任一點(diǎn)起來的線段
A line segment that joins the center of a regular polygon with any of its vertices.
將正多邊形的中心與它的一任一頂點(diǎn)起的來的線段
The length of any such line segment.
半距離：這種線段的長(zhǎng)度
A circular area measured by a given radius:
半徑范圍：以某一半徑所計(jì)的圓形地區(qū)：
例句：
every family within a radius of 25 miles of the city center.
住在離城中心半徑25英里的范圍內(nèi)的家庭

A bounded range of effective activity or influence:
活動(dòng)半徑：有效活動(dòng)或影響的邊界范圍：
例句：
the operating radius of a helicopter.
直升飛機(jī)的作戰(zhàn)半徑

A radial part or structure, such as a mechanically pivoted arm or the spoke of a wheel.
輻射部分：輻射形的部件或結(jié)構(gòu)，如機(jī)械上有軸的臂或車輪的輻條
Anatomy
【解剖學(xué)】
A long, prismatic, slightly curved bone, the shorter and thicker of the two forearm bones, located on the lateral side of the ulna.
橈骨：一種長(zhǎng)的、棱柱狀、微彎的內(nèi)頭，兩根前臂骨中較短較粗的一根，位于尺骨的后側(cè)
A similar bone in many vertebrates.
橈骨：許多脊椎動(dòng)物具有的類似的骨頭

來源：
Latin [ray]
拉丁語 [射線]