Which type of truss is commonly used for peaked roofs due to its triangular geometry?

• A. Pratt truss
• B. Triangular truss
• C. Warren truss
• D. Kingpost truss

Answer: (B)

The idea being tested is that triangular geometry provides inherent rigidity for roof framing. A truss built as triangles resists deformation very well because triangles are stable shapes: when loads push down on the roof, the forces are distributed along the three sides in a way that keeps the frame from distorting. For peaked roofs, that peak shape naturally aligns with a triangular arrangement, giving a stiff, efficient path to transfer loads to the supports.

This makes the triangular truss the best choice because its simple three-sided form creates rigid triangles that hold their shape under load, maintaining the roof’s apex and spreading forces evenly to walls or columns. Other truss variations rearrange diagonals to optimize different spans or load paths, but they don’t embody the same direct link between the peak geometry and unconditional rigidity that triangles provide.