S.83 T.223

a)
\sin53=0{,}798...\approx0{,}8
\frac{y}{1}=\frac{0{,}8}{1}=0{,}8
\cos53=0{,}601...\approx0{,}6
\frac{x}{1}=\frac{0{,}6}{1}=0{,}6
\left(0.6{,}0.8\right)
b) 
180°-143°=37°

\sin37=0{,}601...\approx0{,}6
\frac{y}{1}=\frac{0{,}6}{1}=0{,}6
\cos37=0{,}798...\approx0{,}8
\frac{x}{1}=\frac{-0{,}8}{1}=-0{,}8
\left(-0.8{,}0.6\right)