what is coplanar

In geometry, a set of points, lines, or other geometric objects are coplanar if they lie on the same plane. For example, three points are always coplanar, and if the points are distinct and non-collinear, the plane they determine is unique. However, a set of four or more distinct points will, in general, not lie in a single plane. Two lines in three-dimensional space are coplanar if there is a plane that includes them both. This occurs if the lines are parallel, or if they intersect each other. Two lines that are not coplanar are called skew lines. In coordinate geometry, we can determine whether given points or lines are coplanar.