We have that the formula to find the volume of a triangular pyramid is:
[tex]V=\frac{Bh}{3}[/tex]where B is the area of the base of the pyramid and h is the height of the pyramid. Now, notice the following:
[tex]\begin{gathered} \text{Group 2:} \\ V=\frac{1}{3}(\frac{11\cdot4}{2})\cdot18 \end{gathered}[/tex]in group 2, the area of the base is represented with the expression (11*4)/2.\
Then, the height of the triangular pyramid is 18 inches. Therefore, group 2 found the requested volume