Statement → Reason
1. n ⊥ l → Given
2. n ⊥ m → Given
3. l ∥ m → Theorem: If two lines are perpendicular to the same line then, they are parallel to each other.
4. line p is a transversal line → Definition of a Transversal line.
5. ∠1 ≅ ∠4 → Corresponding Angles Theorem
6. ∠4 + ∠5 = 180 degrees → Definition of a Linear Pair
7. ∠1 + ∠5 = 180 degrees → Substitution Property of Equality
8. ∠1 and ∠5 are supplementary. → Definition of Supplementary Angles