If P × Q = Q × P, the angle between P and Q is θ(0^°<θ<360^°). The value of ' θ ' will be \ \ \ \ °.

If $\displaystyle \vec{P} \times \vec{Q}=\vec{Q} \times \vec{P}$, the angle between $\displaystyle \vec{P}$ and $\displaystyle \vec{Q}$ is $\displaystyle \theta\left(0^{\circ}<\theta<360^{\circ}\right)$. The value of '$\displaystyle \theta$' will be \_\_\_\_°.