\(\vec{M} \times \vec{N} \neq \vec{N} \times \vec{M}\)

\(\vec{M} \times \vec{N}\) is from \(\vec{M}\) to \(\vec{N}\)

\(\vec{N} \times \vec{M}\) is from \(\vec{N}\) to \(\vec{M}\)

This means the two vectors are in opposite direction.

\(\text { So, } \vec{M} \times \vec{N} =\vec{N} \times \vec{M}\)

\(=180^{\circ}\)