The diagonals of a kite intersect at right angles.
A kite is a quadrilateral, with two pairs of congruent adjacent sides, that is named after one of the traditional forms of toy kite. The toy itself probably draws its name from the bird commonly called a kite, or kyte, in England. The old English form of the word, cyte, may in turn derive from an early German name for an owl.
A non-convex kite is often called a dart, a term used by Roger Penrose in his proof on a non-periodic tiling of the plane (see also Penrose tiling). Proclus referred to this shape as a "four-sided triangle" and spoke of it as a geometric paradox. John Conway has pointed out that there is no special name for a quadrilateral that has two pairs of equal sides that, unlike in the case of a kite, are not parallel sides. He proposed the name strombus for such a figure, from the Greek for a spinning top.