Answer:
x = 8 cm
Explanation:
To solve it ,given that it is a right angled triangle.
We can use trigonometry functions
cos 60° = adjacent side / hypotenuse
cos 60° = 4 cm / x
multiply each side by x
x × cos 60° = 4 cm × x / x
x cos 60° = 4 cm
divide each side by cos 60°
x × cos 60°/cos 60° = 4 cm / 60°
x = 4 cm / 0.5 . .( given :- cos 60° =0.4 )
x = 8 cm