## Definition

A dart is an irregular quadrilateral with a reflex angle.

## Also defined as

Some sources prefer to reserve the term dart for a reflex-angled trapezium which has both pairs of adjacent sides equal, for example $EFGH$ in the diagram above.

Other uses restrict the term specifically to the dart in the Penrose tiles.

## Also known as

A dart whose adjacent sides are equal is also called a deltoid.