Use the trigonometric function.
[tex]\sin30^o=\dfrac{x}{20}\\\\\sin30^o=\dfrac{1}{2}\\\\\dfrac{x}{20}=\dfrac{1}{2}\ \ \ |\cdot20\\\\x=10[/tex]
[tex]\sin60^o=\dfrac{y}{20}\\\\\sin60^o=\dfrac{\sqrt3}{2}\\\\\dfrac{y}{20}=\dfrac{\sqrt3}{2}\ \ \ \ |\cdot20\\\\y=10\sqrt3[/tex]
