10 best triangles of the 21st century (so far).

Of late, the New York times has been making headlines (which is of course their prerogative) out of ranking things.

The 100 books of the century.

The 100 movies of the century.

The 25 best pizzas in NYC (inexplicably updated six months later to “The 22 best pizzas in NYC,” portending a grim future where the category of “best pizza places” contracts toward some kind of pizza singularity).

Anyway, I say anyone can play at this game, and I hereby give you…

(And I’m sorry for the snub, 30-60-90-stans.)

EDIT: For future reference, a few other nominations from folks on social media…

• The 13-14-15, whose integer altitude of 12 divides the 14 into 5 and 9 (via Jutta Gut and David Williams)
• The 20-21-29, the smallest Pythagorean triple where c > b + 2 (via Dylan Rambow)
• The 80-80-20, which gives rise to the fabulous constructions of Langley’s Adventitious Angles (via Ng Boong Leong)
• The 3-5-7, which has a 120 degree angle, and can thus be attached to the 5-5-5 equilateral to create a 5-7-8 (via David Williams)
• The 1-i-0 (via lowcheeliang)

Published October 14, 2025October 9, 2025