Từ điển tiếng Anh - Cambridge Advanced Learners Dictionary
radius
radius UK US [ˈreɪ.di.əs] [plural radii ] noun countable [ radii ]
DISTANCE
1. (the length of) a straight line joining the centre of a circle to its edge or the centre of a sphere to its surface • The radius of this wheel is 30 cm. • This wheel has a radius of 30 cm. Thesaurus+: ↑Parts of geometrical shapes 2. a distance • The station, shopping centre and school lie within a one-mile radius of the house. Thesaurus+: ↑Measurements in general
BONE 3. specialized the thicker of the two bones in the lower arm See picture Thesaurus+: ↑The arm