A cantilevered truss is supported on one side only which is designed to be effectively much heavier than the unsupported one, so even adding weight to the unsupported side does not cause it to sag. The parts of a truss are chords (top and bottom) and the web, in a pitched truss, there are two top chord pieces. The pieces of the web in a truss are always in opposition to each other, so if one is in tension, its neighbor is in compression. The top chord is always in compression and the bottom chord is always in tension. The triangles of the truss can be in a variety of configurations, each undoubtedly with its own advantages and disadvantages, but all work on the same general principles.