-Congruent Line Segments-Definition: Line segments are congruent if they have the same length-Line segments are congruent if they have the same length. However, they need not beparallel. They can be at any angle or orientation on the plane. In the figure above, there are two congruent line segments. Note they are laying at different angles. If you drag any of the four endpoints, the other segment will change length to remain congruent with the one you are changing. For line segments, 'congruent' is similar to saying 'equals'. You could say "the length of line AB equals the length of line PQ". But in geometry, the correct way to say it is "line segments AB and PQ are congruent" or, "AB is congruent to PQ".