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:
“It is the vice of our public speaking that it has not abandonment. Somewhere, not only every orator but every man should let out all the length of all the reins; should find or make a frank and hearty expression of what force and meaning is in him.”
—Ralph Waldo Emerson (1803–1882)
“They raise their minds by brooding over and embellishing their sufferings, from one degree of fervid exaltation and dreary greatness to another, till at length they run amuck entirely, and whoever meets them would do well to run them thro’ the body.”
—Thomas Carlyle (1795–1881)
“Men sometimes speak as if the study of the classics would at length make way for more modern and practical studies; but the adventurous student will always study classics, in whatever language they may be written and however ancient they may be. For what are the classics but the noblest recorded thoughts of man?... We might as well omit to study Nature because she is old.”
—Henry David Thoreau (1817–1862)