Can you solve this pier puzzle?

My take on this puzzle b4 watchin d answer:

Draw 2 perpendicular lines from both the towns to the horizontal line above. This will give us 2 pts P & Q on the horizontal line.

Select any pt x between these 2 pts and this pt x can include any of the pts P or Q

Distance between ["Pt x" and "town A"] + distance between ("pt x" and "town B") = Aways the same as all the set of pts including and between the pts P & Q acts as locus.