$r=\sqrt{4^2+2^2}=\sqrt{20}=2\sqrt{5}$  

$\sin \alpha =\frac{2}{2\sqrt{5}}=\frac{\sqrt{5}}{5}$

$\cos \alpha =\frac{4}{2\sqrt{5}}=\frac{2\sqrt{5}}{5}$  

$\mathrm{tg}\alpha =\frac{2}{4}=\frac{1}{2}$  

 

$\sin \left({180}^{\circ }-\alpha \right)=\sin \alpha =\frac{\sqrt{5}}{5}$   

$\cos \left({180}^{\circ }-\alpha \right)=-\cos \alpha =-\frac{2\sqrt{5}}{5}$    

$\mathrm{tg}\left({180}^{\circ }-\alpha \right)=-\mathrm{tg}\alpha =-\frac{1}{2}$