Let's take a look at the diagram we have been given.
Examining the diagram, we see that ∠ABC is a right angle.
m∠ABC= 90^(∘)
We also see that ∠ABC equals the sum of ∠1 and ∠2. Therefore, by the Angle Addition Postulate we can write the following equation.
m∠1+ m∠2= ∠ABC
Using the Substitution Property of Equality, we can prove that the sum of m∠1 and m∠2 equals 90^(∘).
m∠1+ m∠2= ∠ABC, m∠ABC= 90^(∘)
⇕
m∠1+ m∠2= 90^(∘)
Since the sum of ∠1 and ∠2 equals 90^(∘), we know that these angles are complementary. Let's show this as a two-column proof.
