The full question is: My house has an attic consisting of a horizontal regular base of length $2q$ and breadth $2p$ (where $p < q$) and four plane roof sections each at angle $\theta$ to the horizontal. Show that the length of the roof edge is independent of $\theta$ and find the volume of the attic and the surface area of the roof.

Drawing a diagram is your best bet here. Since all the sections are inclined at the same angle, the roof ridge will be central. From your diagram, can you use trigonometry to find the height $h$ of the roof? Once that's done, it shouldn't be too much more work to find the length of the roof ridge in terms of $p$ and $q$, you'll find that $\theta$ disappears. Post your workings if you're still unsure about what's going on.