To determine the wavelength, you need to consider the distance between points A and B, which is given as 6 meters. The wavelength is defined as the overall distance divided by the number of cycles between those points.
If A and B represent one complete cycle of the wave (from crest to crest or trough to trough), then the wavelength is equal to the distance between them, which is 6 meters.
So, the answer is:
6 m