Radius

of a circle

A segment joining a point of the circle (or sphere) to the centre. The length of this segment is also called the radius.

#### Comments[edit]

For the radius of curvature of curves, surfaces and higher-dimensional differential-geometric objects, cf. e.g. Curvature and Differential geometry.

#### References[edit]

[a1] |  M. Berger, "Geometry" , I , Springer (1987)

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[a2] |  H.S.M. Coxeter, "Introduction to geometry" , Wiley (1963)