1. **Problem Statement:** Given that angle 1 is congruent to angle 8 ($\angle 1 = \angle 8$), determine which lines are parallel. 2. **Understanding the Setup:** Lines $l$ and $m$ are horizontal lines intersected by two transversals, creating 16 angles numbered 1 to 16. 3. **Key Concept:** When a transversal crosses two lines, if a pair of corresponding angles are congruent, then the two lines are parallel. 4. **Identify Angles:** Angles 1 and 8 are located such that if they are congruent, they are corresponding angles formed by the transversal intersecting lines $l$ and $m$. 5. **Conclusion:** Since $\angle 1 = \angle 8$ and these are corresponding angles, lines $l$ and $m$ must be parallel. **Final answer:** Lines $l$ and $m$ are parallel.