tetrahedral

A 4-sided shape commonly found within the proper bounds of Euclidian geometry.

Hey, that affine transformation with the tetrahedral sure was exceptionally difficult, good sir.

by Mr. Slartybartfest November 29, 2007

Tetrahedral

An insult that has no meaning but will mentally obliterate anyone it is used against. Only use if you plan on never talking to the victim again.

Chad: "John you are such an absolute fucking tetrahedral"
John: *kills himself*

by Trump gaming October 15, 2020

Tetrahedral number

The {n}th tetrahedral number is the sum of the first n Triangular numbers. Triangular numbers are the sum of the first n integers (1, 3, 6, 10, 15, etc.), and taking the sum of the triangular numbers results in the tetrahedral numbers (1, 4, 10, 20, 35, etc.)

The fifth tetrahedral number is the sum of the first five triangular numbers. The first five triangular numbers are 1, 3=1+2, 6=1+2+3, 10=1+2+3+4, and 15=1+2+3+4+5, so the sum of these numbers is 1+3+6+10+15= 35.

by EmeraldofSeattle December 14, 2008