Coplanar

Coplanarity of points in n dimensions whose coordinates are given

Since three or fewer points are always coplanar, the problem of determining when a set of points is coplanar is generally of interest only when there are at least four points involved. In the case that there are exactly four points, several ad hoc methods can be employed, but a general method that works for any number of points uses vector methods and the property that a plane is determined by two linearly independent vectors.