Answer: C. 12
Explanation:
This is a 30-60-90 triangle. The short leg is always opposite the 30 degree angle. The long leg is opposite the 60 degree angle.
For these types of special triangles, we can say
[tex]\text{long leg} = (\text{short leg})*\sqrt{3}[/tex]
Based on that formula, and the fact that the long leg is [tex]6\sqrt{3}[/tex], this means the short leg must be 6 units long.
For any 30-60-90 triangle, the hypotenuse is twice as long as the short leg
[tex]\text{hypotenuse} = 2*(\text{short leg})[/tex]
So the hypotenuse is 2*6 = 12 units long
