Question

planes q and r are parallel planes. plane q contains line a. plane r contains line b. if a third plane could be drawn which contains both lines a and b, then lines a and b must be parallel. lines a and b cannot be parallel. lines a and b must be skew. lines a and b must be perpendicular.

Explanation:

Step1: Recall plane - line relationship

If two lines lie in the same plane, they are coplanar.

Step2: Analyze given situation

Lines a and b are in parallel planes Q and R respectively. A third - plane contains both a and b, so a and b are coplanar.

Step3: Determine line relationship

Since a and b are in parallel planes and are coplanar (in the third plane), they must be parallel. Skew lines are non - coplanar, and there is no information to suggest they are perpendicular.

Answer:

lines a and b must be parallel.