Answer: Measure from rarefaction to rarefaction
Explanation:
A longitude wave is the one in which particles oscillate in the direction of motion of the wave. The energy is transported via compression and rarefaction. A compression is a region of high density of medium particles and rarefaction is the region of low density. A wavelength of a longitudinal wave can be defined as the distance between a two consecutive rarefaction areas or two consecutive compression areas.
