ANSWER

Step-by-step explanation
In the given diagram, G is the point where all the three medians of the triangle meet.
We call this point of intersection of all the three medians the CENTROID of the triangle.
One property about the centroid is that, the centroid divides the medians in the ratio

The medians are the lines from the vertex to the midpoints of the opposite side of the triangle.
This implies that,


We can rewrite this as,

We cross multiply to obtain,



Therefore CG = 5cm