Common Loon, Common Lune
A field-guide pun: the common loon (a bird) and the common lune (a crescent-shaped geometric region).
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Free for classrooms, worksheets, slides and other non-commercial use under CC BY-NC 4.0, with credit to Ben Orlin.
Cartoon by Ben Orlin, Math with Bad Drawings. https://cartoons.mathwithbaddrawings.com/2019-03-20-common-loon-common-lune/ (CC BY-NC 4.0)Transcript
[Common Loon] a loon on water. [Common Lune] a smiling crescent-shaped lune.