If $| A |=2,| B |=5$ and $| A \times B |=8$ Angle between $A$ and $B$ is acute, then $A \cdot B$ is

The angle between the two vectors $\overrightarrow A = 5\hat i + 5\hat j$ and $\overrightarrow B = 5\hat i - 5\hat j$ will be ....... $^o$

If $\vec{A}$ and $\vec{B}$ are two vectors satisfying the relation $\vec{A} . \vec{B}=[\vec{A} \times \vec{B}]$. Then the value of $[\vec{A}-\vec{B}]$. will be :

When $\vec A.\vec B = - |A||B|,$ then

The angle between vectors $(\vec{M} \times \vec{N})$ and $(\bar{N} \times \vec{M})$ is ................

Let $\vec A\, = \,(\hat i\, + \,\hat j)\,$  and $\vec B\, = \,(2\hat i\, - \,\hat j)\,.$  The magnitude of a coplanar vector $\vec C$ such that  $\vec A\cdot \vec C\, = \,\vec B\cdot \vec C\, = \vec A\cdot \vec B$ is given by