The rule of the volume of the triangular pyramid is
[tex]V=\frac{1}{3}\times\frac{1}{2}\times b\times h\times H[/tex]
b is the base of the triangular base
h is the height of the triangular base
H is the height of the pyramid
From the given figure we can see
The base of the triangular base is 29 cm and its height is 9 cm, then
b = 29
h = 9
Since the volume of the pyramid is 318 cubic cm, then
V= 318
Substitute them in the rule above to find H
[tex]\begin{gathered} 318=\frac{1}{3}\times\frac{1}{2}\times29\times9\times h \\ \\ 318=43.5H \\ \\ \frac{318}{43.5}=H \\ \\ 7.31=H \end{gathered}[/tex]
The height of the pyramid is 7.31 cm
The answer is A
