the prism looks more or less like the picture below.
so in essence, you simply get the area of the bottom, which is the triangle with base of 9 and height of 4, recall that A = 1/2 bh, and then multiply that much times the height of the prism, of 9.5.
[tex]\bf \stackrel{\textit{area of the bottom}}{\left[ \cfrac{1}{2}(9)(4) \right]}\stackrel{\textit{height of the prism}}{(9.5)}[/tex]
