Answer:
In longitudinal wave, wavelength is obtained by measuring the distance from a compression to the next compression or from a rarefaction to the next rarefaction.
Step-by-step explanation:
What is a longitudinal wave?
A longitudinal wave is a wave in which the particles of the medium are displaced in a direction parallel to the direction of energy transport
What is a wave length?
wavelength of a wave is basically the length of one complete wave cycle. The wavelength can always be determined by measuring the distance between any two corresponding points on adjacent waves.