## CGAL::orientation_2

### Definition

The function orientation_2 computes if a polygon is clockwise or counterclockwise oriented.

#include <CGAL/Polygon_2_algorithms.h>

template <class ForwardIterator, class Traits>

Orientation

orientation_2 ( | ForwardIterator first, ForwardIterator last, Traits traits)

Precondition: is_simple_2(first, last, traits);

### Requirements

1. Traits is a model of the concept PolygonTraits_2 . Only the following members of this traits class are used:
   - Less_xy_2
   - less_xy_2_object
   - orientation_2_object
2. ForwardIterator::value_type should be Traits::Point_2,

### See Also

PolygonTraits_2
CGAL::is_simple_2
CGAL::Polygon_2<PolygonTraits_2, Container>
CGAL::Orientation