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English definition of “radius”

radius

noun [C] (DISTANCE)    /ˈreɪ.di.əs/ (plural radii)
(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.Parts of geometrical shapes a distance from a central point : The station , shopping centre and school lie within a one-mile radius of the house .Measurements in general
(Definition of radius noun (DISTANCE) from the Cambridge Advanced Learner's Dictionary & Thesaurus © Cambridge University Press)
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