Subject :IMO Class : Class 9

ABCD is quadrilateral. If AC and BD are its diagonals, then the

ASum of the squares of the sides of the quadrilateral is equal to the sum of the squares of its diagonals.

BPerimeter of the quadrilateral is equal to the sum of the diagonals.

CPerimeter of the quadrilateral is less than the sum of the diagonals.

DPerimeter of the quadrilateral is greater than the sum of the diagonals.