In the concave case it is the extension of one of the diagonals. Any of various usually small hawks family Accipitridae with long narrow wings and often a notched or forked tail. A kite is a member of the quadrilateral family and while easy to understand visually is a little tricky to define in precise mathematical terms.
Definition of Line explained with real life illustrated examples.
Two disjoint pairs of adjacent sides are equal by definition. If a quadrilateral is a square then it is not a kite. That toy kite is based on the geometric shape the kite. Each pair must be adjacent sides sharing a common vertex and each pair must be distinct.