Final answer:
Given that ∠1 and ∠2, as well as ∠3 and ∠4, are complement to each others, Statement 1 is likely the part of the proof that justifies angles with a 90° combined measure. This statement sets the foundation for subsequent parts of the proof.
Step-by-step explanation:
This is a question related to geometry, specifically dealing with the concept of complementary angles. Complementary angles are pairs of angles that add up to 90°.
In the given question, ∠1 is complementary to ∠2 and ∠3 is complementary to ∠4. This means that the measure of ∠1 + ∠2 = 90° and the measure of ∠3 + ∠4 = 90°.
The part of the proof that uses the justification that angles with a combined degree measure of 90° are complementary would be the statement that defines this relationship - likely Statement 1. It's this statement that would establish ∠1 and ∠2 as complementary, laying the groundwork for subsequent steps, including establishing ∠3 as an acute angle.
Learn more about Complementary Angles