Tromino (source code)

= Tromino

= Triomino
{synonym}

= Triominoes
{synonym}

= Trominoes
{synonym}

A <tromino> is a <polyomino> made of three unit <squares> joined along whole sides. Up to <translation>, <rotation> and <reflection>, its two shapes are the straight three-square strip and the L shape. Their <area> is three, so a board tiled by <trominoes> must have <area> divisible by three; that condition alone need not ensure a <board tiling>. For example, a $2\times3$ <rectangle> admits two straight <trominoes>.