Fill in the blank with the most appropriate word. If three points are coplanar, they are __ collinear. a. sometimes b. always c. never

Answer 1

If 3 points are coplanar (lie in the same plane) then they are SOMETIMES collinear (lie on the same line).

For example, the points (0,0,0), (1,1,0) and (2,2,0) lie in the xy-plane and are collinear. However, the points (0,0,0), (1,1,0) and (1,2,0) lie in the xy-plane but are not collinear.

Answer 2

The points are sometimes collinera.