Answer:
x = 19.6
Step-by-step explanation:
By applying cosine rule in ΔBCD,
cos(30)° = 
= 

BC = 
Now, by applying sine rule in ΔBAC,
sin(45)° = 


x = 
x = 19.59
x ≈ 19.6
The answer you have selected is correct
70--you have to round down because its ".2" and not ".5 or above"