Triomino -- from Wolfram MathWorld

A triomino, also known as a tromino, is a 3-polyomino. There are two free polyominoes, (the same) two one-sided polyominoes, and 6 fixed polyominoes. The free polyominoes are known as the L-triomino (or right triomino) and straight triomino, respectively. There is also a game called triomino consisting of 55 equilateral triangles, each containing three numbers from 0 to 5 at each vertex. Every combination of tiles is in the game, although those tiles with three different values are allowed

A (2^k) × (2^k) chessboard has one of its squares missing. Can you

Triomino -- from Wolfram MathWorld

Heptomino -- from Wolfram MathWorld

Un générateur de triominos - latroussemaitresses

Exploring Tetris as a Transformation Semigroup

Règles du Triominos - Comment jouer au Triominos ?

Monotone Triangle -- from Wolfram MathWorld

Domino and Triomino Tilings of a Chessboard

Trigonometry -- from Wolfram MathWorld

Polyplet -- from Wolfram MathWorld

Polyomino -- from Wolfram MathWorld

Trinomial Coefficient -- from Wolfram MathWorld

Fibonacci Cube Graph -- from Wolfram MathWorld

Domino and Triomino Tilings of a Chessboard - Wolfram

Trigonometric Substitution -- from Wolfram MathWorld