SOLUTION:
A simple sketch will help;
We can use the sine rule to solve for the angle B;
Thus;
1/4 (2x - 14) = 4
2x - 14 = 16
2x = 30
x = 15
I think it's B. 168 units
Because I multiplied them all together and halved the answer
Add 2x to both sides,
3x+9=18
Subtract 9 from both sides. 3x=9
Divide both sides by 3.
x=3