Answer:
20.78
Step-by-step explanation:
sin a = perpendicular/ hypotenuse
where a is the base angle
here a = 60
sin 60 = 18/ x
since,
[tex] \sin(60) = \ \frac{ \sqrt{3} }{2}[/tex]
[tex] \frac{ \sqrt{3} }{2} = \frac{18}{x} [/tex]
√3 x = 36
x = 36/ √3
x = 36/ 1.732
x = 20.78