Radius

For other senses of this word, see radius (disambiguation).

In classical geometry, a radius of a circle or sphere is any line segment from its center to its boundary. By extension, the radius of a circle or sphere is the length of any such segment. The radius is half the diameter.

More generally — in geometry, engineering, graph theory, and many other contexts — the radius of something (e.g., a cylinder, a polygon, a graph, or a mechanical part) is the distance from its center or axis of symmetry to its outermost points. In this case, the radius may be more than half the diameter.

See also

• Bend radius
• Curvature
• Diameterbg:Радиус

cs:Poloměr zh-min-nan:Poàⁿ-kèng da:Radius (cirkel) de:Radius eo:Radiuso fr:Rayon (géométrie) gl:Raio is:Radíus it:Raggio (geometria) lt:Spindulys nl:Straal (wiskunde) ja:半径 no:Radius (geometri) pl:Promień pt:Raio ru:Радиус sl:Polmer ta:ஆரம் uk:Радіус zh:半径