CGAL::collinear

bool collinear ( Point_2<Kernel> p, Point_2<Kernel> q, Point_2<Kernel> r)
returns true, iff p, q, and r are collinear.

bool collinear ( Point_3<Kernel> p, Point_3<Kernel> q, Point_3<Kernel> r)
returns true, iff p, q, and r are collinear.

See Also

CGAL::left_turn
CGAL::orientation
CGAL::right_turn