They are coplanar if the line joining any two of them intersects the line joining the other two.
The greatest number is six.
sometimes
Not necessarily, eg the three points (0, 0), (1, 1) and (2,0) are not co-linear, but (0,0), (1,1) and (2,2) are. But three points are co-planar, that is they all lie in one plane.
Since the question is unfinished, I'll assume the most obvious completion: "planes." Yes, a triangular pyramid is composed of 4 non-co-planar points which form 4 intersecting planes.
co-planar
The greatest number is six.
sometimes
Not necessarily, eg the three points (0, 0), (1, 1) and (2,0) are not co-linear, but (0,0), (1,1) and (2,2) are. But three points are co-planar, that is they all lie in one plane.
Since the question is unfinished, I'll assume the most obvious completion: "planes." Yes, a triangular pyramid is composed of 4 non-co-planar points which form 4 intersecting planes.
Yes, three points define a plane. So any three points lie in some specific plane and are therefore co-planar.
Yes. A circle is defined as the set of all points in a plane equidistant from a given point (the center of the circle) - hence - all points of a circle must be co-planar by definition.
co-planar
Co-planar means being in the same plane.
co-planar
In Cartesian co-ordinates, the points (0,0), (4,0), (4,4) and (0,4) are an example of the four vertices of a rectangle.
Parallel lines will be co-planar.
The difference is that one is co-linear force is one dimensional and co-planar force is 2-dimensional. Co-linear force is the force which is acting along a single line, whereas co-planar force is the force which is acting along a single plane.