In geometric measurements, length most commonly refers to the longest dimension of an object.
In certain contexts, the term "length" is reserved for a certain dimension of an object along which the length is measured. For example it is possible to cut a length of a wire which is shorter than wire thickness. Another example is FET transistors, in which the channel width may be larger than channel length.
Length may be distinguished from height, which is vertical extent, and width or breadth, which are the distance from side to side, measuring across the object at right angles to the length.
Length is a measure of one dimension, whereas area is a measure of two dimensions (length squared) and volume is a measure of three dimensions (length cubed). In most systems of measurement, the unit of length is a fundamental unit, from which other units are defined.
Famous quotes containing the word length:
“I have seen some whose consciences, owing undoubtedly to former indulgence, had grown to be as irritable as spoilt children, and at length gave them no peace. They did not know when to swallow their cud, and their lives of course yielded no milk.”
—Henry David Thoreau (1817–1862)
“He thought he saw an Elephant,
That practiced on a fife:
He looked again, and found it was
A letter from his wife.
“At length I realize,” he said,
“The bitterness of Life!””
—Lewis Carroll [Charles Lutwidge Dodgson] (1832–1898)
“Oft have I mused, but now at length I find,
Why those that die, men say they do depart.”
—Sir Philip Sidney (1554–1586)