Final answer:
In this question, we have three pairs of lines and we need to identify whether they are skew, parallel, or intersecting.
Step-by-step explanation:
In this question, we are given three pairs of lines: bar (DE) and bar (CF), bar (AD) and bar (AC), and bar (BE) and bar (CF).
(i) Skew refers to lines that do not intersect and are not parallel. Since bar (DE) and bar (CF) do not intersect and do not lie on the same plane, they are skew lines.
(ii) Parallel lines are lines that always stay the same distance apart and never meet. In this case, bar (AD) and bar (AC) are parallel lines because they lie on the same plane and do not intersect.
(iii) Intersecting lines are lines that cross each other at some point. Therefore, bar (BE) and bar (CF) are intersecting lines because they cross each other at the point F.