What are the $x$ and $y$ components of a $25 \mathrm{m}$ displacement which is at an angle of $210°$ with the $x$-axis (anti-clockwise)?

One of the rectangular components of a velocity of $60 \mathrm{km} {\mathrm{h}}^{-1}$ is $30 \mathrm{km} {\mathrm{h}}^{-1}$. The other rectangular component is $x\sqrt{3} \mathrm{km} {\mathrm{h}}^{-1}$. Find $x$.

If $0.5\hat{\mathrm{i}}+0.8\hat{\mathrm{j}}+c\hat{\mathrm{k}}$ is a unit vector, find the value of $\pm c\frac{10}{\sqrt{11}}$.

If $\left|\overrightarrow{A}\right|=4,\left|\overrightarrow{B}\right|=3$ and $\theta =60°$ in the figure, find $\frac{{\left(|\overrightarrow{A}\times \overrightarrow{B}|\right)}^2}{\left(\overrightarrow{A}·\overrightarrow{B}\right)}$.