File:Polygonal lake - median line.svg

Licensing
I don't mind this being moved to Commons but I don't see any point in doing so. This diagram is merely to illustrate a discussion in project space on enwp. https://en.wikipedia.org/w/index.php?title=Wikipedia:Reference_desk/Mathematics&oldid=765248414#Sizes_of_polygonal_lakes Associated file: File:Polygon for measurements of lake.svg