13. Collinear means the three points lie on a line. For instance, A, C, and E are collinear.
14. A, C, and D do not lie on the same line, so they are not collinear.
15. Coplanar means the four points are in the same plane. For example, B, C, D, and F lie in the same plane and are coplanar.
16. Yes, the hash marks indicate the lengths are equal.
17. No, there is no evidence the lines are equal in length.
