<Dd> K = 1 2 x 1 y 2 − x 2 y 1 . (\ displaystyle K = (\ tfrac (1) (2)) x_ (1) y_ (2) - x_ (2) y_ (1).) </Dd> <P> In the following table it is listed if the diagonals in some of the most basic quadrilaterals bisect each other, if their diagonals are perpendicular, and if their diagonals have equal length . The list applies to the most general cases, and excludes named subsets . </P> <Table> <Tr> <Th> Quadrilateral </Th> <Th> Bisecting diagonals </Th> <Th> Perpendicular diagonals </Th> <Th> Equal diagonals </Th> </Tr> <Tr> <Th> Trapezoid </Th> <Td> No </Td> <Td> See note 1 </Td> <Td> No </Td> </Tr> <Tr> <Th> Isosceles trapezoid </Th> <Td> No </Td> <Td> See note 1 </Td> <Td> Yes </Td> </Tr> <Tr> <Th> Parallelogram </Th> <Td> Yes </Td> <Td> No </Td> <Td> No </Td> </Tr> <Tr> <Th> Kite </Th> <Td> See note 2 </Td> <Td> Yes </Td> <Td> See note 2 </Td> </Tr> <Tr> <Th> Rectangle </Th> <Td> Yes </Td> <Td> No </Td> <Td> Yes </Td> </Tr> <Tr> <Th> Rhombus </Th> <Td> Yes </Td> <Td> Yes </Td> <Td> No </Td> </Tr> <Tr> <Th> Square </Th> <Td> Yes </Td> <Td> Yes </Td> <Td> Yes </Td> </Tr> </Table> <Tr> <Th> Quadrilateral </Th> <Th> Bisecting diagonals </Th> <Th> Perpendicular diagonals </Th> <Th> Equal diagonals </Th> </Tr>

Shapes with diagonals that are not equal in length