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Diameter Facts for Kids. *Kiddle Encyclopedia.*

In geometry, the **diameter** of a circle is a line from one side directly to the opposite side through the centre. It can also be defined as the longest chord of a circle. These can both describe the diameter in a sphere too.

The letter *d* or the symbol **⌀** are often used as a symbol for the diameter. The diameter's length is often called the diameter itself.

The diameter's length is twice the radius, and therefore the relationship between the diameter's length and radius can be shown with the equations:

and

All content from Kiddle encyclopedia articles (including the article images and facts) can be freely used under Attribution-ShareAlike license, unless stated otherwise. Cite this article:

Diameter Facts for Kids.