CGAL::side_of_oriented_circle

Oriented_side	side_of_oriented_circle ( Point_2<R> p, Point_2<R> q, Point_2<R> r, Point_2<R> test)
		returns the relative position of point test to the oriented circle defined by $$p, $$q and $$r. The order of the points $$p, $$q and $$r is important, since it determines the orientation of the implicitly constructed circle. Precondition: p, q and r are not collinear.

See Also

CGAL::side_of_bounded_circle