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.
no,three points can be non collinear
As defined by Math Open Reference: collinear points are points that lie on the same line. Any series of points with a yvalue of 4, for example, will be collinear since they lie on the same line. Lines formed by collinear points can have any slope and be located anywhere on a co-ordinate plane. The Math Open Reference link shows a working visual example of collinear points.
It's not possible to say without seeing the drawing.
because coplanar is coplanar and collinear is collinear!!
Yes, collinear points are also coplanar.
No but they are always coplanar.
Any set of points that are collinear must be coplanar.
Not sure about complanar. Coplanar lines can be collinear but need not be.
No, two points are always collinear. I think 3 points are always coplanar.
3 coplanar points may or may not be collinear. 3 collinear points must be coplanar.
A set of 3 points will always be coplanar, but will only sometimes be collinear. Collinear points are always coplanar as well.