Centroid theorem: the centroid is 2/3 of the distance from each vertex to the midpoint of the opposite side.
For the given triangle:
[tex]XM=\frac{2}{3}XA[/tex]
XA is the sum of XM and MA:
[tex]XA=XM+MA[/tex]
Use the two equations above to find MA:
[tex]\begin{gathered} XM=8 \\ \\ 8=\frac{2}{3}XA \\ \\ XA=\frac{3}{2}(8) \\ \\ XA=12 \\ \\ \\ 12=8+MA \\ MA=12-8 \\ \\ MA=4 \end{gathered}[/tex]Then, MA is equal to 4
