Dear student,
Two lines are said to be parallel when they do not meet at any point in a plane. Lines that do not have a common intersection point and never cross paths with each other are parallel to each other. Parallel lines can be defined as two lines in the same plane that are at equal distance from each other.
But, there is no such condition that states parallel lines are of the same lengths.
The distance between the two lines is always the same, but the length of the lines does not matter for being parallel.
So,
It is not necessary for parallel lines to be of the same length.
Regards!