Using the sine formula;
sin 60 / x = sin 90 / 16
cross-multiply
x sin 90 = 16 sin 60
Divide both-side of the equation by sin 90
x = 16 sin 60 /sin 90
x= 13.86
To find y, we can simply use the Pythagoras theorem
opp² + adj² = hyp²
13.86² + y² = 16²
192.0996 + y² =256
subtract 192.0996 from both-side of the equation
y² = 256 - 192.0996
y² = 63.9004
Take the square root of both-side
y = 7.99