The diagonals of a parallelogram are 2 i and 2 j. The area of parallelogram is

Let the sides of the parallelogram be A and B. ThenA+B=2i and A-B=2j∴ A = i+j and B = i -jNow area of parallelogram =|A×B|=|(i+j)×(i−j)|=|(−i×j+j×i)|=|−k−k|=2 units