Explanation:
A truss is a structural framework made up of triangular sections that are connected by straight members. The triangular shape of the truss provides stability and strength to the structure.

Types of Trusses:
There are different types of trusses based on their configuration and the arrangement of their members. These include:

1. Simple Truss: A simple truss is the most basic type of truss structure. It consists of straight members connected at joints to form triangular sections. The members only experience axial forces and are either in tension or compression. This type of truss is commonly used in bridges, roofs, and towers.

2. Complex Truss: A complex truss is a more intricate truss structure that contains additional members, such as diagonals or verticals, to provide additional support and stability. It may have more than one triangular section or incorporate other shapes besides triangles. Complex trusses are used when there is a need for extra load-carrying capacity or when architectural aesthetics require a different configuration.

3. Lateral Truss: A lateral truss is a specialized type of truss that is used to resist lateral loads, such as wind or earthquake forces, in addition to vertical loads. It is designed to provide lateral stability to the structure and prevent it from collapsing or buckling under these loads. Lateral trusses are commonly used in tall buildings, bridges, and other structures that are subjected to significant lateral forces.

Equilateral Truss:
An equilateral truss is not a recognized type of truss. The term "equilateral" refers to a triangle in which all three sides are equal in length. While equilateral triangles are often used in the construction of trusses, it does not define a specific type of truss structure. Trusses can be made up of equilateral triangles, isosceles triangles, or any other combination of triangles, depending on the design requirements.

Therefore, the correct answer to the given question is option 'B' - Simple Truss. The triangular section in a truss refers to the arrangement of members in the shape of triangles, which is a characteristic feature of a simple truss structure.