A truss is a structural system made up of a collection of elements connected at pin joints or nodes. The members of a truss are predominantly axially loaded, meaning they are either in compression, tension, or have no force, so-called zero-force members. Trusses are typically composed of triangles because of the structural stability of that shape and design. A triangle is the simplest geometric figure that will not change shape when the lengths of the sides are fixed. Trusses are used in engineering to create rigid structures that can span large distances. They are commonly used in bridge designs due to their ability to efficiently span long distances. Trusses are also used in roof framing, where they can cut framing costs by as much as 50%. There are many common forms or patterns of truss that have emerged in response to different use cases, such as the Pratt, Howe, Warren, and Modified Warren. The benefit of a truss is that the members are axially loaded, so there is no shear or bending, making them a very efficient structural component.