Question

The base of a triangular prism (read: triangular prism!) has a base of 5 cm and a height of 8 cm. The prism itself has a height of 7 cm. What is its volume?

Answer 1

The volume of any right prisim is given by $V = A_b \times h$ where $A_b$ is the area of the base and $h$ is the height. 

In this case, the base is a triangle and so its area can be found thus:
$A = \frac{1}{2} b \times h$

So:
$V= A_b \times h_p$
$V=(\frac{1}{2} \times {b} \times h_b) \times h_p$
$V=(\frac{1}{2} \times {5cm} \times 8cm) \times 7cm$
$V=20cm^{2} \times 7cm$
$V=140cm^{3}$