$\displaystyle \frac{1}{2}$\displaystyle \frac{1}{2}

$\displaystyle \frac{2}{\sqrt{5}}$\displaystyle \frac{2}{\sqrt{5}}

$\displaystyle \frac{1}{\sqrt{5}}$\displaystyle \frac{1}{\sqrt{5}}

$\displaystyle \frac{\sqrt{3}}{2}$\displaystyle \frac{\sqrt{3}}{2}