\begin{definition}[Definition:Linear Measure/Length]
'''Length''' is linear measure taken in a particular direction.
Usually, in multi-dimensional figures, the dimension in which the linear measure is greatest is referred to as '''length'''.
It is the most widely used term for linear measure, as it is the standard term used when only one dimension is under consideration.
'''Length''' is the fundamental notion of Euclidean geometry, never defined but regarded as an intuitive concept at the basis of every geometrical theorem.
\end{definition}