CGAL 5.6.1  2D Conforming Triangulations and Meshes

#include <CGAL/Delaunay_mesh_criteria_2.h>
The class Delaunay_mesh_criteria_2
is a model for the MeshingCriteria_2
concept.
The shape criterion on triangles is given by a bound \( B\) such that for good triangles \( \frac{r}{l} \le B\) where \( l\) is the shortest edge length and \( r\) is the circumradius of the triangle. By default, \( B=\sqrt{2}\), which is the best bound one can use with the guarantee that the refinement algorithm will terminate. The upper bound \( B\) is related to a lower bound \( \alpha_{min}\) on the minimum angle in the triangle:
\[ \sin{ \alpha_{min} } = \frac{1}{2 B} \]
so \( B=\sqrt{2}\) corresponds to \( \alpha_{min} \ge 20.7\) degrees.
CDT  must be a 2D constrained Delaunay triangulation. 
Creation  
Delaunay_mesh_criteria_2 ()  
Default constructor with bound \( B=\sqrt{2}\).  
Delaunay_mesh_criteria_2 (double b=0.125)  
Construct a traits class with bound \( B=\sqrt{\frac{1}{4 b}}\).  