Answer:
x ≈ 19.7
Step-by-step explanation:
Using the sine ratio in the right triangle.
sin66° = [tex]\frac{opposite}{hypotenuse}[/tex] = [tex]\frac{18}{x}[/tex] ( multiply both sides by x )
x × sin66° = 18 ( divide both sides by sin66° )
x = [tex]\frac{18}{sin66}[/tex] ≈ 19.7 ( to the nearest tenth )