Answer:
Explanation:
You see that there’re angles with 30 and 90 degrees that means that -> 180-(90+30)=60 (measurement of the third angle)
Here you’ll need to use the 30,60,90 degree triangle rule:
The opposite side of 30 degree will be y
30->y
90->2y->12√3 => y=6√3
60->y√3->x => 6√3x√3=6x3=18
To understand the rule better you can check the picture below.Wish it will help you!Good luck!