% tri.mesh
%
% The first line lists the number of elements, and their type.
%
% The type code is:
% 1: 2D triangular elements (vertices can be listed in any order)
% 2: 3D tetrahedral elements (vertices can be listed in any order)
% 3: 3D hexahedral (brick) elements
% (vertices must be listed in a particular order)
% 4: 2D quadrilateral elements.
% (vertices must be listed in a particular order)
%
5 1
%
% The following lines list the vertices making up each element.
%
1 2 3
2 4 6
2 6 3
4 5 6
5 6 3