Final answer:
Triangles are commonly used in trusses because they are stable and can distribute forces evenly. They help to support the weight and distribute the load throughout the structure.
Step-by-step explanation:
In trusses, the geometric figure commonly used is a triangle.
Triangles are used in trusses because they are stable and can distribute forces evenly. Trusses are structures made up of interconnected triangles, which help to support the weight and distribute the load throughout the structure. This makes trusses strong and rigid.
For example, in a truss bridge, the triangular shape of the trusses helps to distribute the weight of the bridge evenly, keeping it sturdy and stable.