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English definition of “radius”

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radius

noun [C]  /ˈreɪ·di·əs/ ( plural radii  /ˈreɪ·diˌɑɪ/) us  
geometry (the length of) a straight line from the center of a circle to its edge: The supermarket, shopping mall, and school are all within a one-mile radius of the house (= are all less than a mile away from it).
(Definition of radius from the Cambridge Academic Content Dictionary © Cambridge University Press)
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