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In geometry, a diameter of a circle is any straight line segment that passes through the center and whose endpoints are on the circular boundary, or, in more modern usage, the length of such a line segment. When using the word in the more modern sense, one speaks of the diameter rather than a diameter, because all diameters of a circle have the same length. This length is twice the radius.The diameter of a connected graph is the distance between the two vertices which are furthest from each other. The distance between two vertices a and b is the length of the shortest path connecting them (for the length of a path, see Graph theory).
The two definitions given above are special cases of a more general definition. The diameter of a subset of a metric space is the least upper bound of the distances between pairs of points in the subset. So, if A is the subset, the diameter is
- sup { d(x, y) | x, y in A } .
Diameter symbol
The symbol or variable for diameter is similar in size and design to ø, the lowercase letter o with stroke. Unicode provides character number 8960 ( hexadecimal 2300) for the symbol, which can be encoded in HTML webpages as ⌀ or ⌀. Proper display of this character, however, is unlikely in most situations, as most fontIn typography, a typeface is a co-ordinated set of character designs, which usually comprises an alphabet of letters, a set of numerals and a set of punctuation marks. There are also typefaces of Ideograms and symbols (e. mathematical or map making) In its do not have it included. (Your browser displays ⌀ and ⌀ in the current font.) In most situations the letter ø is acceptable, obtained in WindowsImage use policy. Microsoft Windows is a range of commercial operating environments for personal computers. The range was first introduced by Microsoft in 1985 and eventually has come to dominate the world personal computer market. All recent versions of by holding the [Alt] key down while entering 0 2 4 8 on the numeric keypad.
It is important not to confuse a diameter symbol (ø) with the empty setAbstract algebra Algebra Set theory In mathematics, the empty set is the set with no elements. Notation The standard notation for denoting the empty set, invented by Nicholas Bourbaki, is the symbol , also written as or ∅, and sometimes approximated symbol, similar to the uppercase Ø. Diameter is also sometimes called phi (pronounced the same as "fee"), although this seems to come from the fact that Ø and ø look like Φ and φ, the letter phi in the Greek alphabetThe Greek language is written in the Greek alphabet developed in classical times (around the 9th century BC) and passed down to the present. In ancient Greece, its letters were also used to represent numbers, called Greek numerals, in analogy with Roman n.
See also: angular diameterThe angular diameter of an object as seen from a given position is the diameter measured as an angle. It satisfies the formula. In astronomy the size of objects in the sky are often measured in terms of their angular diameter as seen from Earth, rather th, hydraulic diameterThe hydraulic diameter, is commonly used term when handling flow in noncircular tubes and channels. Using this term one can calculate many things in the same way as for a round tube. Definition: where A is the cross-sectional area and U is the wetted peri
