1. **Problem Statement:** Identify which pairs of lines in the cube are skew lines. Skew lines are lines that are neither parallel nor intersecting and do not lie in the same plane. 2. **Recall definitions:** - Parallel lines: lines in the same plane that never intersect. - Intersecting lines: lines that cross at a point. - Skew lines: lines that are not parallel, do not intersect, and are not coplanar. 3. **Analyze each pair:** - **TX and WX:** Both share point X, so they intersect. Not skew. - **RS and TU:** RS is on the top face edge, TU connects top and bottom faces. They do not intersect and are not parallel. Check if coplanar: RS lies on the top face plane, TU is vertical edge connecting top to bottom. They are not in the same plane, so skew. - **UY and WX:** UY is on the bottom face diagonal, WX is on the top face edge. They do not intersect and are not parallel. They lie on different planes, so skew. - **TX and VW:** TX connects top to bottom face diagonally, VW is an edge on the bottom face. They do not intersect and are not parallel. They lie in different planes, so skew. 4. **Conclusion:** The skew line pairs are RS and TU, UY and WX, TX and VW. **Final answer:** RS and TU, UY and WX, TX and VW are skew lines.