Can you identify lines that are perpendicular? 1. Tap Add. 2. Find a set of perpendicular lines. Use to trace the lines. 3. Find a set of crossing lines that are not perpendicular. Use another color to trace them. 4. Label the lines you identified. 5. Use or to and tell how you know the lines are perpendicular, or not perpendicular. 6. Upload to your journal.