Final answer:
Line segments of the same length are described as congruent. This term indicates they have identical size and shape, differing from terms like parallel or perpendicular, which refer to orientation.
Step-by-step explanation:
Line segments with the same length are said to be congruent. The term congruent is used in geometry to describe figures, shapes, or line segments that have the same size and shape. In the case of line segments, congruent segments have exactly the same length, regardless of their orientation or position. This is not to be confused with the term parallel, which describes lines or segments that never intersect because they are always the same distance apart; nor should it be mistaken for perpendicular segments, which intersect at a 90-degree angle.