1) Since, the given triangle is a right triangle, and you have both an angle and the hypotenuse length, you can use some trigonometric ratios to find the variables.
2) The variables given represent:
x: adjacent-leg to angle 30° y: opposite length to angle 30°
3) sine ratio:
sin 30° = opposite-leg / hypotenuse = y / (16√3)
⇒ y = 16√3 sin 30° = 16√3 × (1/2) = 8√3
4) cosine ratio
cos 30° = adjacent-leg / hypotenuse = x / (16√3)
⇒ x = 16√3 cos 30° = 16√3 (√3 / 2) = 16 × 3 / 2 = 24