Answer:
27
Explanation:
The centroid divide a median in two parts, with ratio 1/3 and 2/3.
In particular the part between the centroid and the point where the median touches the side is 1/3 of the median.
We can build this proportion:
ST : 1/3 = IT : 3/3
9 : 1/3 = IT : 1
IT = 9 * 3 = 27