Pythagoras
publication date: Wednesday, June 20, 2018 (part of Summer 2018)
category: Philosophy
clue: It's not as popular as E = mc², but this ancient philospher's calculation that a² + b² = c² continues to be a cornerstone of children's first geometry classes.
intended difficulty: very easy
solved by: Russ Wilhelm, Samir Mehta, Chris Lemler, Richard Slominsky, and Matthew Preston