It would be nice if there are some answer choices, but it's ok. From my understanding of the 30-60-90 triangle this would be the answer.
If the length of the longer leg of a 30-60-90 triangle is x, then the length of the shorter leg is half the length of the hypotenuse and the length of the hypotenuse is double the length of the shorter leg.
This is because of the 1:square root of 3:2 ratio of the 30-60-90.
If this isn't the answer you were looking for, just comment, because I don't know if your looking for a specific answer.