# Lune (geometry)

In plane geometry, the crescent shape formed from two intersecting circles is called a lune (in gray). There are two lunes in each diagram only one of which is shaded |

See also: Spherical lune

In plane geometry, a **lune** is the concave-convex area bounded by two circular arcs, while a convex-convex area is termed a lens. ^{[1]} The word "lune" derives from *luna*, the Latin word for Moon.

Formally, a lune is the relative complement of one disk in another (where they intersect but neither is a subset of the other). Alternatively, if A and B are disks, then is a lune.

## Example

In the 5th century BC, Hippocrates of Chios showed that certain lunes could be exactly squared by straightedge and compass.

## See also

Wikimedia Commons has media related to .Crescents |

## References

- ↑ "Google Groups". Groups.google.com. Retrieved 2015-12-27.

## External links

- The Five Squarable Lunes at MathPages

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