a) $\frac{\sin60^\circ\cdot2\cot30^\circ}{(\cos45^\circ)^2}$
b) $\frac{\sin45^\circ+\cos60^\circ}{\cos30^\circ}$
c)$\left(\frac{\sqrt{2}\sin30^\circ+\sqrt{3}\cos60^\circ}{\tan30^\circ\cdot\cos0^\circ\cdot2\sin60^\circ}\right)^{-2}$
č)$\frac{\left(\sin30^\circ-\cos30^\circ\right)^{2}-\cot45^\circ}{\cot60^\circ+\tan30\circ}$

$b=$ 3 $\sqrt{3}~$cm
$\beta=$ 60 $^\circ$


Izračunaj dolžini stranic $a$ in $b$.