Answer:
15
Explanation:
The first thing we have to do is find angle A
I will assume that you know SOH CAH TOA (if not ,ask)
We will use TOA
Tan(angle)=5/10
angle= 26.565
Now that we know angle A we will look at these two triangles as one big one
We know that side CA=30 and that anglea=26.56 so we can use TOA again
Tan(26.565)=x/30
30tan(26.565)=x
x=15