Final answer:
To complete the two-column proof, statement 4 should be 'q ⊥ r' because if ∠1 ≅ ∠2 and p is perpendicular to r, then q must also be perpendicular to r.
Step-by-step explanation:
To complete the two-column proof, we need to find a statement that shows that q is perpendicular to r, just like p is perpendicular to r.
We know that ∠1 ≅ ∠2, which means that the angles formed by p and q are congruent. Since p is perpendicular to r, ∠p will be 90 degrees. Therefore, ∠q will also be 90 degrees, making q perpendicular to r.
So the statement that completes the proof is: q ⊥ r.