check the picture below.
so, the house is really just a triangular prism sitting on top of a rectangular prism.
the volume of the triangular prism is just product of the area of the triangular face and its length.
the volume of the rectangular prism is very straightforward, length * width * height.
so the volume of the house is the sum of both volumes.
[tex]\bf \stackrel{\textit{volume of triangular prism}}{\stackrel{\textit{area of triangle}}{\left[ \cfrac{1}{2}(1.8)(0.7) \right]}\cdot 1.1}~~~~~~+~~~~~~\stackrel{\textit{volume of the rectangular prism}}{(1.1)(1.8)(0.7)}[/tex]
