A simple truss is built from a basic triangular structure. When more triangles are added to prevent collapse, the truss becomes statically indeterminate. To design a truss, forces in each member must be determined first, then appropriate sizes and shapes selected to withstand those forces.

1. 2. Simple Trusses
▪ Simple Truss:
• The basic element of a plane truss is the triangle.
• Four or more bars pin-jointed to form a polygon of as many
sides constitute a no rigid frame.
(rigid mean no collapsible and induced internal strains is negligible)

2. 2. Simple Trusses
▪ Simple Truss:
• Structures built from a basic triangle,
- known as simple trusses
• When more needed to prevent collapse,
- the truss is statically indeterminate.
• To design a truss,
- first determine the forces in the various members
- and then select appropriate sizes
and structural shapes to withstand the forces.