Answer:

Step-by-step explanation:
This is a 30-60-90 triangle.
It's good to remember this. The side length opposite to the 60 degree angle is always the base multiplied by
I think it's 12x.
I'm not a 100% sure though, but I hope this helps. =^D
The value of x is 5. Angle one and four are vertical. You can do this by writing 7x = 3x + 20. Isolate the variable by moving 3x to the other side. If you do this, 3x becomes negative, and you end up with 7x-3x = 20 --> 4x = 20.
x=5.