What is the wavelength of the waves shown below?

Question

the height from the center line to the top of the wave is 5meters and the width is 8 meters

Answer 1

A wave's wavelength is the distance between subsequent maxima or minimum (hills or valleys). If, in the graph for this problem, one crest of a wave is 8 meters across, then its wavelength is 8 meters.

Check this answer by finding two points on the wave that are at the exact same height (e.g. 5 meters). Calculate the horizontal distance between those two points. The resulting answer is your wavelength.