Answer:
[tex] \huge\: x =9 \sqrt{ \boxed{3}} [/tex]
Step-by-step explanation:
Given is a 30°-60°-90° triangle and x is the length of side opposite to 60° angle.
[tex] \therefore \: x = \frac{ \sqrt{3} }{2} \times 18 \\ \\ \therefore \: x = \sqrt{3} \times 9 \\ \\ \huge\therefore \: x =9 \sqrt{ \boxed{3}} [/tex]
