ABCD is a parallelogram with −−→AC and −−→BD as diagonals. Then −−→AC−−−→BD=

ABCD is a parallelogram with −−→AC and −−→BD as diagonals.

1.	ABCD is a parallelogram with −−→AC and −−→BD as diagonals. Then −−→AC−−−→BD=
Answer» $A B C D$ is a parallelogram with $- - \to A C$ and $- - \to B D$ as diagonals. Then $- - \to A C - - - \to B D =$