Constant strain triangle element

The Constant Strain Triangle (CST) element is a type of finite element used in structural analysis, particularly for 2D problems involving triangular geometries. It is one of the simplest elements employed in the finite element method (FEM) and is utilized for modeling elastic and plastic behavior of materials. ### Key Features of CST Element: 1. **Geometry**: The CST element is triangular in shape and is defined by three nodes. Each node corresponds to a vertex of the triangle.