**Triangles are used in construction because they provide sturdy foundations to various infrastructures.** Due to their rigid forms, triangles can withstand tremendous pressure.

Triangles are closed plane figures with three sides and three angles. They can be classified according to the number of congruent sides or the type of angle these polygons contain. Triangles can be scalene, isosceles or equilateral based on their sides or they can be acute, right or obtuse based on their angles.

Triangular frameworks are commonly used in building or bridge construction. One technique in architecture, called tangent and radical trussing, uses a truss made up of triangular components that provide structural support for a bridge.