Let's begin by identifying key information given to us:
We have triangle CDE
J is the centroid
[tex]\begin{gathered} JG=21 \\ \text{The centroid of a triangle divides }\frac{2}{3\text{ }}\text{the distance from}verte\text{x to midpoint of the sides} \\ \Rightarrow JG=\frac{2}{3}CG \\ \Rightarrow21=\frac{2}{3}CG=\frac{63}{2} \\ \therefore CG=\frac{63}{2}=31.5 \end{gathered}[/tex]
