1. **State the problem:** We are given angles and lines in a diagram and need to identify pairs of lines or angles based on their relationships: perpendicular lines, parallel lines, alternate angles, corresponding angles, and co-interior angles. 2. **Important definitions and rules:** - **Perpendicular lines:** Two lines that intersect at a right angle (90°). - **Parallel lines:** Two lines that never meet and are always the same distance apart. - **Alternate angles:** Angles on opposite sides of a transversal but inside the parallel lines; they are equal. - **Corresponding angles:** Angles in the same relative position at each intersection where a transversal crosses parallel lines; they are equal. - **Co-interior angles:** Angles on the same side of the transversal and inside the parallel lines; their sum is 180°. 3. **Identify pairs:** - **Perpendicular lines:** Given lines E and F are perpendicular. - **Parallel lines:** Lines A and B are parallel, and lines C and D are parallel. - **Alternate angles:** Angles J and K form a pair of alternate angles. - **Corresponding angles:** Since the problem does not specify exact angles for corresponding angles, but based on the diagram, a pair could be angles a and b (or any other corresponding pair). - **Co-interior angles:** Angles c and d form a pair of co-interior angles. 4. **Summary:** - Perpendicular lines: E + F - Parallel lines: A + B, C + D - Alternate angles: J + K - Corresponding angles: a + b - Co-interior angles: c + d This completes the identification based on the given diagram and angle relationships.