sin θ = opposite/hypotenuse & tan θ = opposite/adjacent sin 30 = 18/y tan 30 = 18/x y = 18/sin 30 x = 18/tan 30 y = 36 x ≈ 31.2
you can also use the 30° - 60° - 90° shortcuts side opposite 30 = a, side opposite 60 = a√3, side opposite 90 = 2a then, 18 = a x = a√3= 18√3 y = 2a = 2(18) = 36