my $coll = new TriangleCollection();

my $t1 = $coll->add_triangle(   A => [$x1,$y1,$z1],
                                B => [$x2,$y2,$z2],
                                C => [$x3,$y3,$z3]
                            );
                                
my $t2 = $coll->add_triangle(   A => [$x4,$y4,$z4],
                                B => [$x5,$y5,$z5],
                                C => [$x6,$y6,$z6]
                            );

$t1->connect_to(    triangle => $t2,
                    my_corner => 'C',
                    other_corner => 'A'
                );