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. The same explanations can be also used to describe the diameter in a sphere.
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.
- "List of Geometry and Trigonometry Symbols". Math Vault. 2020-04-17. Retrieved 2020-09-24.
- "Basic information about circles (Geometry, Circles)". Mathplanet. Retrieved 2020-09-24.
- Weisstein, Eric W. "Circle". mathworld.wolfram.com. Retrieved 2020-09-24.