all of them are collinear they lie in the same plane
Yes, since any line can be contained in a plane.
lie on the same plane and are collinear
Yes. On any straight line you can find an infinite set of 4 points which are collinear.
Two points are collinear if there is a line going through them. A higher-dimensional counterpart to this is "coplanar": objects are coplanar if there is a plane that contains the objects. There's always a plane containing any three points, so you'd need at least four points (in at least three dimensions) for this distinction to be meaningful. However, it's also possible to discuss two or more coplanar lines, for example - if two lines are not coplanar, they are called skew. To visualize this, imagine a bridge crossing a river: the bridge and the river could be extended into lines that are not contained in any common plane. Beyond coplanar objects, it's possible to discuss "cospatial" objects that lie in the same three-dimensional space. However, you'd need at least four dimensions to even talk about this, since in three dimensions everything is cospatial, in a way. Another related concept to collinear is "concurrent." This refers to three or more lines (or circles) that all intersect at the same point.
Yes, they are.
not necassarily
all of them are collinear they lie in the same plane
Yes, since any line can be contained in a plane.
lie on the same plane and are collinear
-lie in the same plane -are collinear
They need not be. The four vertices of a quadrilateral are coplanar but NOT collinear. On the other hand, any line (in Eucledian geometry) has an infinite number of points on it - all of which are coplanar.
Three or more points are collinear if they are all in the same straight line. They are non collinear if at least one of them is not on the same line as the rest. Four or more points are coplanar if they are all in the same plane. They are non coplanar if at least one of them is not on the same plane as the rest.
I dont think that "If four points are collinear they are also coplaner," is the same thing as "If four points are coplaner they are also collinear,". The definition of collinear is at least three points on the same line. To define a plane is to have threenoncollinear points.
exactly nine planes! * * * * * I would have said 4 - corresponding to the four faces of a tetrahedron. Of course, non-collinear does not mean non-coplanar so all four points could be in the same single plane!
The answer depends on the number of point. One point - as the question states - cannot be non-collinear. Any two points are always collinear. But three or more points will define a plane. If four points are non-coplanar, they will define four planes (as in a tetrahedron).
No. If the four points are coplanar, they determine only one plane!