-lie in the same plane -are collinear
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.
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. A trinagle does not require four points, three are sufficient. And any three points, if they are not colinear, must be coplanar.
space
Yes, they are.
Yes, they are.
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!