My last tutor said the height of the prism is 5 but I'm not sure what the area of the base is.


The base of the prism is the triangle.
The area of the triangle (B) is:
[tex]B=\frac{b\cdot h}{2}[/tex]where:
b is the base of the triangle = 7.2.
h = height of the triangle.
Substituting the values:
[tex]\begin{gathered} B=\frac{7.2}{2}\cdot h \\ B=3.6\cdot h \end{gathered}[/tex]Answer:
[tex]B=3.6\cdot h[/tex]