Yes, this is a special right triangle such that the short leg (opposite 30 deg. angle) is half the length of the hypotenuse.
Therefore x=2*9=19,
and therefore, using Pythagoras theorem,
y=sqrt(18^2-9^2)=sqrt(324-81)=9sqrt(2^2-1^2)
=9sqrt(3)
=15.588 (to 3 decimal places).
