Hello Delanew,
Do you mean the altitude of the triangle, since you are already given the length?
If you are looking for an altitude, you can start by drawing it in your triangle. You will see that it divides the triangle into two 30, 60, 90 triangles. The short leg of the triangle is 6, so using the rules for a 30, 60, 90 triangle the longer leg (your altitude) would be 6 square roots of 3. Or about 10.39.
If this isn't what you are looking for, let me know.
I can try and help.
Good luck!
