The method that can be used to find the volume of the house is:
Add the volume of a rectangular prism to the volume of the triangular prism.
<h2>Step-by-step explanation:</h2>
In order to find the volume of the house we need to find the volume of the bottom part of the house which in the shape of a rectangular prism or cuboid and volume of the top of the house which is in the shape of a triangular prism.
Hence, the total volume of the house is:
Volume of rectangular prism+Volume of triangular prism.