Why is the obtuse triangle always upset?

The joke about the perpetually gloomy obtuse triangle hinges entirely on a clever bit of wordplay. "Right" is the star here, doing double duty. In geometry, a "right" triangle is one that contains a 90-degree angle, a fundamental concept. But in everyday language, "right" also means correct, just, or even emotionally sound and happy. The obtuse triangle, by definition, has an angle greater than 90 degrees, meaning it can never be a *right* triangle in the mathematical sense.

This geometric fact is then humorously twisted into an emotional state. The poor obtuse triangle is "never right" not just because it lacks a specific angle, but because it's perpetually off-kilter, never quite fitting in, and therefore always a bit sad or upset. This kind of pun, where a technical term is given a relatable human emotion, is a staple of observational humor, especially in the often-dry world of mathematics. It's a gentle reminder that even the most precise fields can yield some delightfully silly wordplay, turning abstract concepts into surprisingly relatable characters.