Characterizations
A quadrilateral is a kite if and only if any one of the following conditions is true:
- Two disjoint pairs of adjacent sides are equal (by definition).
- One diagonal is the perpendicular bisector of the other diagonal. (In the concave case it is the extension of one of the diagonals.)
- One diagonal is a line of symmetry (it divides the quadrilateral into two congruent triangles).
- One diagonal bisects a pair of opposite angles.
Read more about this topic: Kite (geometry)