Triangle jerk 

Term used for a group of three people jerking off in triangular fashion because they don't have enough people to make a circle. Common among mathematically-savvy academics.

Alan: what kind of triangle jerk should we try this time?
Bryce: let's try the isosceles.

Triangle jerk by abbadabba22 February 10, 2010

trianglejerk 

The most popular triangle related subreddit. A place for geniuses to congregate and discuss triangles.

Obama: How did you cure cancer?
Trianglejerker: Oh, i just copied the cure from trianglejerk.

trianglejerk by YourStepMother September 5, 2011