$\"\"$

\

If $\"\"$ is the angle between non zero vectors $\"\"$ and $\"\"$ , then $\"\"$ .

\

$\"\"$

\

Let the vectors are $\"\"$ and $\"\"$ .

\

The angle $\"\"$ between vectors $\"\"$ and $\"\"$ is $\"\"$ .

\

Find the cross product :

\

$\"\"$

\

$\"\"$

\

Find the magnitudes :

\

Magnitude of $\"\"$ is $\"\"$ .

\

$\"\"$

\

Magnitude of $\"\"$ is $\"\"$ .

\

$\"\"$

\

$\"\"$

\

The angle $\"\"$ between vectors $\"\"$ and $\"\"$ is $\"\"$ .

\

$\"\"$

\

$\"\"$

\

The angle between the vectors formed by the oxygen-hydrogen bonds is about $\"\"$ .